0001437749-21-003413 | 10-K | XBRL Viewer

Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]

Note 1 — Nature of Business

Organization and business

Proto Labs, Inc. and its subsidiaries (Proto Labs, the Company, we, us, or our) is an e-commerce driven digital manufacturer of quick-turn, on-demand injection-molded, computer numerical control (CNC) machined, 3D-printed and sheet metal-fabricated custom parts for prototyping and short-run production. The Company’s customers are product developers and engineers throughout the world who require a faster and less expensive way to obtain low volumes of parts. The Company’s proprietary technology eliminates most of the time-consuming and expensive skilled labor conventionally required to quote and manufacture parts in low volumes, and its customers conduct nearly all of their business with the Company over the Internet. The Company targets its product lines to the millions of product developers and engineers who use three-dimensional (3D) computer-aided design (CAD) software to design products across a diverse range of end-markets. The Company has established operations in the United States, Europe and Japan, which the Company believes are among the largest geographic markets where these product developers and engineers are located. The Company’s primary manufacturing product lines currently include Injection Molding, CNC Machining, 3D Printing and Sheet Metal. Proto Labs, Inc. is headquartered in Maple Plain, Minnesota. The Company’s subsidiaries are:

	Name		Location

	PL-US International LLC		United States
	Proto Labs Ltd.		United Kingdom
	PL International Holdings, UK, Ltd.		United Kingdom
	PL Euro Services Limited		United Kingdom
	Proto Labs GmbH		Germany
	Proto Labs Tooling GmbH		Germany
	Proto Labs, G.K.		Japan

Note 2 - Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2020

Significant Accounting Policies [Text Block]

Note 2 — Summary of Significant Accounting Policies

Principles of consolidation

The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries, as listed within “Organization and business” above. All intercompany accounts and transactions have been eliminated in consolidation.

Comprehensive income

Components of comprehensive income include net income and foreign currency translation adjustments. Comprehensive income is disclosed in the accompanying consolidated statements of comprehensive income and consolidated statements of shareholders’ equity.

Accounting estimates

The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America (U.S. GAAP) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and related disclosures at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.

Cash and cash equivalents

Cash and cash equivalents include cash and other investments, including marketable securities, with maturities of three months or less at the date of purchase. The Company maintains its cash in bank deposit accounts, which, at times, may exceed federally insured limits. The Company has not experienced any losses on such accounts.

Marketable securities

Marketable securities include held-to-maturity debt securities recorded at amortized cost. Management determines the appropriate classification of debt securities at the time of purchase and reevaluates such designation as of each balance sheet date. Debt securities are classified as held-to-maturity when the Company has the positive intent and ability to hold the securities to maturity. Held-to-maturity securities are stated at amortized cost, adjusted for amortization of premiums and accretion of discounts to maturity computed under the effective interest method. Such amortization is included in other income, net. Interest on securities classified as held to maturity is included in other income, net. The classification of marketable securities as current or non-current is dependent upon the security’s maturity date. Securities with maturities of three months or less at the time of purchase are categorized as cash equivalents as described above. During the first quarter of 2020, the Company adopted the FASB ASU 2016-13, Financial Instruments – Credit Losses. The Company calculated the expected credit loss for each security in its portfolio using the probability-of-default method. The Company concluded the adoption of the guidance had no material impact on its consolidated financial statements.

Accounts receivable and allowance for doubtful accounts

Accounts receivable are reported at the invoiced amount less an allowance for doubtful accounts. As of each balance sheet date, the Company evaluates its accounts receivable and establishes an allowance for doubtful accounts based on a combination of specific customer circumstances and credit conditions taking into account the history of write-offs and collections. A receivable is considered past due if payment has not been received within the period agreed upon in the invoice. Accounts receivable are written off after all collection efforts have been exhausted. Recoveries of trade receivables previously written off are recorded when received.

Inventory

Inventory consists primarily of raw materials, which are recorded at the lower of cost or market, using the average cost method, which approximates first-in, first-out (FIFO) cost. The Company periodically reviews its inventory for slow-moving, damaged and discontinued items and provides allowances to reduce such items identified to their recoverable amounts.

Property, equipment and leasehold improvements

Property, equipment and leasehold improvements are stated at cost. Major improvements that substantially extend an asset’s useful life are capitalized. Repairs, maintenance and minor improvements are charged to operations as incurred. Depreciation, including amortization of leasehold improvements and assets recorded under capital leases, is calculated using the straight-line method over the estimated useful lives of the individual assets and ranges from 3 to 39 years. Manufacturing equipment is depreciated over 3 to 15 years, office furniture and equipment are depreciated over 3 to 7 years, computer hardware and software are depreciated over 3 to 5 years, building costs are depreciated over 39 years, leasehold improvements are depreciated over the estimated lives of the related assets or the life of the lease, whichever is shorter, and building and land improvements are depreciated over 10 to 39 years. Assets not in service are not depreciated until the asset is put into use.

The Company follows ASC 350-40, Internal-Use Software, in accounting for internally developed software. As of December 31, 2020 and 2019, respectively, $49.4 million and $32.7 million of software development costs were capitalized. Capitalized software development costs for the year ended December 31, 2020 were $16.7 million.

Goodwill

The Company recognizes goodwill in accordance with ASC 350, Intangibles—Goodwill and Other. Goodwill is the excess of cost of an acquired entity over the amounts assigned to assets acquired and liabilities assumed in a business combination. Goodwill is not amortized. Goodwill is tested for impairment annually in the fourth quarter of each year, and is tested for impairment between annual tests if an event occurs or circumstances change that would indicate the carrying amount may be impaired. An impairment charge for goodwill is recognized only when the estimated fair value of a reporting unit, including goodwill, is less than its carrying amount. In 2020, the Company performed a qualitative analysis based on the significance of the fair value over the carrying value in prior period assessments. As of December 31, 2020, no impairment charges for goodwill have been recognized.

Capitalized Software Costs

The Company follows ASC 350-40, Intangibles – Goodwill and Other, Internal-Use Software, in accounting for internally developed software. Costs for internal use software are evaluated by projected and capitalized where appropriate.

Other Intangible Assets

Other intangible assets include software technology, customer relationships and other intangible assets acquired from other independent parties. Other intangible assets with a definite life are amortized over a period ranging from two to 10 years on a straight line basis, and are tested for impairment whenever events or circumstances indicate that the carrying amount of an asset (asset group) may not be recoverable. An impairment loss is recognized when the carrying amount of an asset exceeds the estimated undiscounted cash flows generated by the asset. The amount of the impairment loss recorded is calculated by the excess of the asset’s carrying value over its fair value.

Accounting for long-lived assets

The Company periodically reviews the carrying amount of its property, equipment and leasehold improvements to determine if circumstances exist indicating an impairment or if depreciation periods should be modified. If facts or circumstances indicate that an impairment may exist, the Company will prepare a projection of the undiscounted future cash flows of the specific assets to determine if the assets are recoverable. If impairment exists based on these projections, an adjustment will be made to reduce the carrying amount of the specific assets to fair value.

Revenue recognition

The Company recognizes revenue in accordance with ASC 606, Revenue from Contracts with Customers. The Company manufactures custom parts to specific customer orders that have no alternative use to the Company, and the Company believes there is a legally enforceable right to payment for performance completed to date on these manufactured parts. For manufactured parts that meet these two criteria, the Company will recognize revenue over time. Revenue is recognized over time using the input method based on time in production as a percentage of total estimated production time to measure progress toward satisfying performance obligations using the estimated total time necessary to complete the parts per the customer's order and an estimate of inventory and production costs incurred to date. The majority of the Company’s injection molding contracts have multiple performance obligations including one obligation to produce the mold and a second obligation to produce parts. For injection molding contracts with multiple performance obligations, the Company allocates revenue to each performance obligation based on its relative standalone selling price. The Company generally determines standalone selling price based on the price charged to customers.

Leases

The Company accounts for leases in accordance with ASC 842, Leases, which requires the balance sheet recognition of lease assets and lease liabilities by lessees for those leases classified as operating and finance leases. The Company determines if an arrangement is a lease at inception. Operating and finance leases are included in operating and finance lease assets, current operating and finance lease liabilities and long-term operating and finance lease liabilities in the Consolidated Balance Sheets and are recognized based on the present value of lease payments over the lease term at commencement date.

Income taxes

The Company accounts for income taxes in accordance with ASC 740, Income Taxes (ASC 740). Under this method, the Company determines tax assets and liabilities based upon the differences between the financial statement carrying amounts and the tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to affect taxable income. The tax consequences of most events recognized in the financial statements are included in determining income taxes currently payable. However, because tax laws and financial accounting standards differ in their recognition and measurement of assets, liabilities and equity, revenues, expenses, gains and losses, differences arise between the amount of taxable income and pretax financial income for a year and between the tax basis of assets or liabilities and their reported amounts in the financial statements. Because the Company assumes that the reported amounts of assets and liabilities will be recovered and settled, respectively, a difference between the tax basis of an asset or liability and its reported amount in the balance sheet will result in a taxable or a deductible amount in some future years when the related liabilities are settled or the reported amounts of the assets are recovered, giving rise to a deferred tax asset or liability. The Company establishes a valuation allowance for any portion of its deferred tax assets that the Company believes may not be recognized.

ASC 740 also clarifies the accounting for uncertainty in income taxes recognized in an enterprise’s financial statements by requiring that individual tax positions are recorded only when they meet a more-likely-than-not criterion. The Company recognizes the effect of income tax positions only if sustaining those positions is more likely than not. The Company records penalties and interest related to unrecognized tax benefits in income taxes in the Company’s Consolidated Statements of Income.

Stock-based compensation

The Company accounts for stock-based compensation in accordance with ASC 718, Compensation—Stock Compensation (ASC 718). Under the fair value recognition provisions of ASC 718, the Company measures stock-based compensation cost at the grant date fair value and recognizes the compensation expense over the requisite service period, which is the vesting period, using a straight-line attribution method. The amount of stock-based compensation expense recognized during a period is based on the portion of the awards that are ultimately expected to vest. The Company accounts for forfeitures as they occur. Ultimately, the total expense recognized over the vesting period will only be for those awards that vest. The Company’s awards are not eligible to vest early in the event of retirement, however, the awards vest early in the event of a change in control.

In determining the compensation cost of the options granted, the fair value of options granted has been estimated on the date of grant using the Black-Scholes option-pricing model.

Advertising costs

Advertising is expensed as incurred and was approximately $11.5 million, $13.0 million and $11.8 million for the years ended December 31, 2020, 2019 and 2018, respectively.

Research and development

Research and development expenses consist primarily of personnel and outside service costs related to the development of new processes and product lines, enhancements of existing product lines, development of software for internal use, maintenance of internally developed software, quality assurance and testing. Costs for internal use software are evaluated by project and capitalized where appropriate under ASC 350-40, Intangibles - Goodwill and Other, Internal-Use Software. Research and development costs were approximately $36.9 million, $32.7 million and $28.7 million for the years ended December 31, 2020, 2019 and 2018, respectively.

Foreign currency translation/transactions

The Company translated the balance sheets of its foreign subsidiaries at period-end exchange rates and the income statement at the average exchange rates in effect throughout the period. The Company has recorded the translation adjustment as a separate component of consolidated shareholders’ equity. Foreign currency transaction gains and losses are recognized in the consolidated statements of comprehensive income.

Recently adopted accounting pronouncements

During the first quarter of 2020, the Company adopted the Financial Accounting Standards Board (FASB) Accounting Standards Update (ASU) 2016-13, Financial Instruments – Credit Losses, which is intended to provide financial statement users with more decision-useful information about the expected credit losses on financial instruments held by a reporting entity at each reporting date. The adoption of this guidance had no material impact on our consolidated financial statements.

During the first quarter of 2019, the Company adopted the FASB ASU 2016-02, Leases (ASC 842), which introduces the balance sheet recognition of lease assets and lease liabilities by lessees for those leases classified as operating leases under previous guidance. The Company has adopted the new lease standard using the new transition option issued under the amendments in ASU 2018-11, Leases, which allowed the Company to continue to apply the legacy guidance in Accounting Standards Codification (ASC) 840, Leases, in the comparative periods presented in the year of adoption. The Company elected the package of practical expedients permitted under the transition guidance within the new standard, which among other things, allowed the Company to carry forward the historical lease classification. The Company made an accounting policy election to keep leases with an initial term of 12 months or less off of the balance sheet. The Company will recognize those lease payments in the Consolidated Statements of Comprehensive Income on a straight-line basis over the lease term. The impact of the adoption was an increase to the Company’s operating lease assets and liabilities on January 1, 2019 of $13.1 million.

Recently issued accounting pronouncements

In December 2019, the FASB issued ASU 2019-12, Income Taxes, which is intended to simplify the accounting for income taxes. This guidance will be effective for fiscal years beginning after December 15, 2020 and interim periods within those fiscal years with early adoption permitted. The Company is evaluating the impact of future adoption of this guidance on its consolidated financial statements, but does not expect the impact to be material.

Note 3 - Revenue

12 Months Ended

Dec. 31, 2020

Revenue from Contract with Customer [Text Block]

Note 3 – Revenue

The Company accounts for revenue in accordance with ASC 606, Revenue from Contracts with Customers. The Company provides quality, quick-turn prototyping and on-demand manufacturing services. As a result, the majority of revenue recognized in a reporting period is based on completed, invoiced contracts.

A performance obligation is a promise in a contract to transfer a distinct good or service to the customer, and is the unit of account in ASC 606. The majority of the Company’s CNC machining, 3D printing, and sheet metal contracts have a single performance obligation. The majority of the Company’s injection molding contracts have multiple performance obligations including one obligation to produce the mold and a second obligation to produce parts. For injection molding contracts with multiple performance obligations, we allocate revenue to each performance obligation based on its relative standalone selling price. We generally determine standalone selling price based on the price charged to customers.

The Company manufactures parts that have no alternative use to the Company since the parts are custom made to specific customer orders, and the Company believes there is a legally enforceable right to payment for performance completed to date on these manufactured parts. For manufactured parts that meet these two criteria, the Company will recognize revenue over time. Revenue is recognized over time using the input method based on time in production as a percentage of total estimated production time to measure progress toward satisfying performance obligations using the estimated total time necessary to complete the parts per the customer's order and an estimate of inventory and production costs incurred to date.

Revenue by geographic region for the years ended December 31, 2020, 2019 and 2018 was as follows:

	*Year Ended December 31,*
(in thousands)	*2020*		*2019*		*2018*
Revenue:
United States	$	345,708	$	360,205	$	350,535
Europe		74,796		82,805		80,889
Japan		13,891		15,718		14,172
Total revenue	$	434,395	$	458,728	$	445,596

Revenue by product line for the years ended December 31, 2020, 2019 and 2018 was as follows:

	*Year Ended December 31,*
(in thousands)	*2020*		*2019*		*2018*
Revenue:
Injection Molding	$	217,992	$	217,415	$	210,523
CNC Machining		131,587		155,473		153,521
3D Printing		62,502		61,352		53,342
Sheet Metal		18,838		21,000		24,998
Other Revenue		3,476		3,488		3,212
Total revenue	$	434,395	$	458,728	$	445,596

The Company generally expenses sales commissions when incurred because the amortization period would have been one year or less. These costs are recorded within marketing and sales expenses. The value of unsatisfied performance obligations for contracts with an original expected length of one year or less is not material.

The entire disclosure of revenue from contract with customer to transfer good or service and to transfer nonfinancial asset. Includes, but is not limited to, disaggregation of revenue, credit loss recognized from contract with customer, judgment and change in judgment related to contract with customer, and asset recognized from cost incurred to obtain or fulfill contract with customer. Excludes insurance and lease contracts.

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Reference 10: http://www.xbrl.org/2003/role/disclosureRef
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Note 4 - Net Income Per Common Share

12 Months Ended

Dec. 31, 2020

Earnings Per Share [Text Block]

Note 4 – Net Income Per Common Share

Basic net income per share is computed based on the weighted average number of common shares outstanding. Diluted net income per share is computed based on the weighted average number of common shares outstanding, increased by the number of additional shares that would have been outstanding had the potentially dilutive common shares been issued and reduced by the number of shares the Company could have repurchased from the proceeds from issuance of the potentially dilutive shares. Potentially dilutive shares of common stock include stock options and other stock-based awards granted under stock-based compensation plans and shares committed to be purchased under the employee stock purchase plan.

The following table presents the calculation of net income per basic and diluted share attributable to common shareholders:

	*Year Ended December 31,*
(in thousands, except share and per share amounts)	*2020*		*2019*		*2018*

Net Income	$	50,867	$	63,655	$	76,588

Basic - weighted-average shares outstanding:		26,737,425		26,866,985		26,982,614
Effect of dilutive securities:
Employee stock options and other		158,932		182,438		296,202
Diluted - weighted-average shares outstanding:		26,896,357		27,049,423		27,278,816
Net income per share attributable to common shareholders:
Basic	$	1.90	$	2.37	$	2.84
Diluted	$	1.89	$	2.35	$	2.81

Note 5 - Goodwill and Other Intangible Assets

12 Months Ended

Dec. 31, 2020

Goodwill and Intangible Assets Disclosure [Text Block]

Note 5 – Goodwill and Other Intangible Assets

The changes in the carrying amount of goodwill for the years ended December 31, 2020 and 2019 were as follows:

(in thousands)	*Dec. 31, 2018*		*Goodwill acquired during 2019*		*Dec. 31, 2019*		*Goodwill acquired during 2020*		*Dec. 31, 2020*

United States	$	123,883	$	-	$	123,883	$	-	$	123,883
Europe		4,239		-		4,239		-		4,239
Japan		630		-		630		-		630
Total goodwill	$	128,752	$	-	$	128,752	$	-	$	128,752

Intangible assets other than goodwill for the years ended December 31, 2020 and 2019 were as follows:

	*Year Ended December 31, 2020*							*Year Ended December 31, 2019*								*Weighted Average Useful Life*
(in thousands)	*Gross*		*Accumulated Amortization*			*Net*		*Gross*		*Accumulated Amortization*			*Net*		*Useful Life (in years)*	*Remaining (in years)*
Intangible Assets with finite lives:
Marketing assets	$930		$(620		)	$310		$930		$(527		)	$403		10.0	3.3
Non-compete agreement	270		(238		)	32		270		(222		)	48		2.0 - 5.0	2.3
Software technology	13,229		(3,645		)	9,584		13,229		(2,275		)	10,954		10.0	7.3
Customer relationships	10,070		(5,646		)	4,424		10,070		(4,106		)	5,964		6.0 - 9.0	2.8
Total intangible assets	$	24,499	$	(10,149	)	$	14,350	$	25,829	$	(8,460	)	$	17,369

Amortization expense for intangible assets for the years ended December 31, 2020, 2019 and 2018 was $3.0 million, $3.5 million and $3.2 million, respectively.

Estimated aggregated amortization expense based on the current carrying value of the amortizable intangible assets is as follows:

(in thousands)	*Estimated Amortization Expense*
2021	$	3,016
2022		3,016
2023		2,813
2024		1,400
2025		1,369
Thereafter		2,736
Total estimated amortization expense	$	14,350

Note 6 - Fair Value Measurements

12 Months Ended

Dec. 31, 2020

Fair Value Disclosures [Text Block]

Note 6 – Fair Value Measurements

ASC 820, Fair Value Measurement (ASC 820), defines fair value as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. ASC 820 also establishes a fair value hierarchy which requires classification based on observable and unobservable inputs when measuring fair value. There are three levels of inputs that may be used to measure fair value:

Level 1—Quoted prices in active markets for identical assets or liabilities.

Level 2—Observable inputs other than Level 1 prices such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.

Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.

The Company’s cash equivalents measured at fair value as of December 31, 2020 and 2019, respectively, consist of money market mutual funds. The Company determines the fair value of these financial assets using Level 1 inputs.

The following tables summarizes financial assets as of December 31, 2020 and 2019 measured at fair value on a recurring basis:

	*December 31, 2020*						*December 31, 2019*
(in thousands)	*Level 1*		*Level 2*		*Level 3*		*Level 1*		*Level 2*		*Level 3*

Financial Assets:
Cash and cash equivalents
Money market mutual funds	$	55,378	$	-	$	-	$	68,962	$	-	$	-
Total	$	55,378	$	-	$	-	$	68,962	$	-	$	-

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

Note 7 - Marketable Securities

12 Months Ended

Dec. 31, 2020

Investment [Text Block]

Note 7 – Marketable Securities

The Company invests in short-term and long-term agency, municipal, corporate and other debt securities. The securities are categorized as held-to-maturity and are recorded at amortized cost. Categorization as held-to-maturity is based on the Company’s ability and intent to hold these securities to maturity. Information regarding the Company’s short-term and long-term marketable securities as of December 31, 2020 and 2019 is as follows:

	*December 31, 2020*
(in thousands)	*Amortized Cost*		*Unrealized Gains*		*Unrealized Losses*			*Fair Value*

U.S. government agency securities	$	18,500	$	6	$	(10	)	$	18,496
Corporate debt securities		42,048		211		(11	)		42,248
U.S. municipal securities		25,003		83		(2	)		25,084
Commercial paper		2,499		-		-			2,499
Certificates of deposit/time deposits		5,395		93		-			5,488
Total marketable securities	$	93,445	$	393	$	(23	)	$	93,815

	*December 31, 2019*
(in thousands)	*Amortized Cost*		*Unrealized Gains*		*Unrealized Losses*			*Fair Value*

U.S. government agency securities	$	6,274	$	1	$	(7	)	$	6,268
Corporate debt securities		26,944		80		(12	)		27,012
U.S. municipal securities		10,204		9		(3	)		10,210
Commercial paper		3,491		-		-			3,491
Certificates of deposit/time deposits		1,484		22		-			1,506
Total marketable securities	$	48,397	$	112	$	(22	)	$	48,487

Fair values for the corporate debt securities are primarily determined based on quoted market prices (Level 1). Fair values for the U.S. government agency securities, U.S. municipal securities, commercial paper and certificates of deposit are primarily determined using dealer quotes or quoted market prices for similar securities (Level 2).

During the first quarter of 2020, the Company adopted the FASB ASU 2016-13, Financial Instruments – Credit Losses. The Company calculated the expected credit loss for each security in its portfolio using the probability-of-default method. The Company concluded the adoption of the guidance had no material impact on its consolidated financial statements.

Classification of marketable securities as current or non-current is based upon the security’s maturity date as of the date of these financial statements.

The December 31, 2020 balance of held-to-maturity debt securities by contractual maturity is shown in the following table at amortized cost. Actual maturities may differ from contractual maturities because the issuers of the securities may have the right to prepay obligations without prepayment penalties.

	*December 31,*
(in thousands)	*2020*

Due in one year or less	$	34,088
Due after one year through five years		59,357
Total marketable securities	$	93,445

Note 8 - Property and Equipment

12 Months Ended

Dec. 31, 2020

Property, Plant and Equipment Disclosure [Text Block]

Note 8 – Property and Equipment

Property and equipment consists of the following:

	*December 31,*
(in thousands)	*2020*			*2019*

Land	$	14,028		$	14,098
Buildings and improvements		77,285			75,843
Machinery and equipment		221,301			208,954
Computer hardware and software		79,207			24,953
Leasehold improvements		7,821			7,341
Construction in progress		33,780			54,313
Total		433,422			385,502
Accumulated depreciation and amortization		(150,756	)		(121,790	)
Property and equipment, net	$	282,666		$	263,712

Depreciation expense for the years ended December 31, 2020, 2019 and 2018 was $29.6 million, $27.4 million and $23.5 million, respectively.

Note 9 - Inventory

12 Months Ended

Dec. 31, 2020

Inventory Disclosure [Text Block]

Note 9 – Inventory

Inventory consists primarily of raw materials, which are recorded at the lower of cost or market using the average-cost method, which approximates first-in, first-out (FIFO) cost. The Company periodically reviews its inventory for slow-moving, damaged and discontinued items and provides allowances to reduce such items identified to their recoverable amounts.

The Company’s inventory consists of the following:

	*December 31,*
(in thousands)	*2020*			*2019*

Total inventory		11,122			10,319
Allowance for obsolescence		(260	)		(244	)
Inventory, net of allowance	$	10,862		$	10,075

Note 10 - Financing Obligations

12 Months Ended

Dec. 31, 2020

Debt Disclosure [Text Block]

Note 10 – Financing Obligations

The Company had no financing obligations as of December 31, 2020 and 2019.

Note 11 - Employee Benefit Plans

12 Months Ended

Dec. 31, 2020

Retirement Benefits [Text Block]

Note 11 – Employee Benefit Plans

The Company maintains a 401(k) retirement plan that covers employees in the United States. Under the plan, a full-time or regular part-time (over 20 hours/week) employee becomes a participant after completing three months of employment. Employees may elect to contribute up to 50 percent of regular gross pay, subject to federal law limits on the dollar amount that participants may contribute to the plan, each calendar year. The Company matches part of the employee contributions and may make a discretionary contribution to the plan. Total employer contributions were approximately $3.3 million, $3.1 million and $2.7 million for the years ended December 31, 2020, 2019 and 2018, respectively.

The Company also sponsors a defined contribution retirement plan that covers the employees in the United Kingdom. Total employer contributions were approximately $0.5 million for the year ended December 31, 2020 and approximately $0.3 million in each of the years ended December 31, 2019 and 2018.

The entire disclosure for retirement benefits.

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Note 12 - Stock-based Compensation

12 Months Ended

Dec. 31, 2020

Share-based Payment Arrangement [Text Block]

Note 12 – Stock-Based Compensation

The Company has two equity incentive plans: the 2000 Stock Option Plan (2000 Plan) and the 2012 Long-Term Incentive Plan (2012 Plan). Upon the adoption of the 2012 Plan on February 21, 2012, all shares that were reserved but not issued under the 2000 Plan were assumed by the 2012 Plan. No additional awards will be issued under the 2000 Plan. Under the 2012 Plan, the Company has the ability to grant stock options, stock appreciation rights (SARs), restricted stock, performance stock, stock units, other stock-based awards and cash incentive awards. Awards under the 2012 Plan have a maximum term of ten years from the date of grant. The compensation committee of the board of directors may provide that the vesting or payment of any award will be subject to the attainment of specified performance measures in addition to the satisfaction of any continued service requirements, and the compensation committee will determine whether such measures have been achieved. The per share exercise price of stock options and SARs granted under the 2012 Plan generally may not be less than the fair market value of a share of our common stock on the date of the grant. Restricted stock is valued at fair market value on the date of grant.

The Company’s 2012 Employee Stock Purchase Plan (ESPP) allows eligible employees to purchase a variable number of shares of the Company’s common stock at a discount through payroll deductions of up to 15 percent of their eligible compensation, subject to plan limitations. The ESPP provides for six-month offering periods with a single purchase period, and at the end of each offering period, employees are able to purchase shares at 85 percent of the lower of the fair market value of the Company’s common stock on the first trading day of the offering period or on the last trading day of the offering period. The Company determines the fair value stock-based compensation related to its ESPP in accordance with ASC 718 using the component measurement approach and the Black-Scholes standard option pricing model.

Employees purchased 42,235 and 41,615 shares of common stock under the ESPP at an average exercise price of $85.85 and $86.70 during 2020 and 2019, respectively. As of December 31, 2020, 1,126,595 shares remained available for future issuance under the ESPP.

The Company determines its stock-based compensation in accordance with ASC 718, which requires the measurement and recognition of compensation expense for all share-based payment awards made to employees and non-employee directors based on fair value.

Determining the appropriate fair value model and calculating the fair value of stock option grants requires the input of subjective assumptions. The Company uses the Black-Scholes option pricing model to value its stock option awards. Stock-based compensation expense is calculated using the Company’s best estimates, which involve inherent uncertainties and the application of management’s judgment. Significant estimates include its expected term and stock price volatility.

The expected term of stock options is estimated from the vesting period of the award and represents the weighted average period that the Company's stock options are expected to be outstanding. The Company estimates the volatility of its stock price based on the historic volatility of its common stock. The Company bases the risk-free interest rate that it uses in the Black-Scholes option pricing model on U.S. Treasury instruments with maturities similar to the expected term of the award being valued. The Company has never paid and does not anticipate paying, any cash dividends in the foreseeable future and, therefore, the Company uses an expected dividend yield of zero in the option pricing model. The Company accounts for forfeitures as they occur. The Company allocates stock-based compensation expense on a straight-line basis over the requisite service period.

The following table summarizes stock-based compensation expense for the years ended December 31, 2020, 2019 and 2018, respectively:

	*Year Ended December 31,*
(in thousands)	*2020*		*2019*		*2018*

Stock options and other	$	13,327	$	9,591	$	10,113
Employee stock purchase plan		1,346		1,190		815
Total stock-based compensation expense	$	14,673	$	10,781	$	10,928

Cost of revenue	$	2,451	$	2,056	$	1,543
Operating expenses:
Marketing and sales		3,121		2,632		1,942
Research and development		2,440		1,851		1,517
General and administrative		6,661		4,242		5,926
Total stock-based compensation expense	$	14,673	$	10,781	$	10,928

Stock Options

The following table provides the assumptions used in the Black-Scholes option pricing model for the years ended December 31, 2020, 2019 and 2018:

	*Year Ended December 31,*
	*2020*		*2019*		*2018*

Risk-free interest rate		0.50 - 1.47%		2.35 - 2.58%		2.52 - 3.07%
Expected life (years)		6.25		6.25		6.25
Expected volatility		42.40 - 43.83%		42.52 - 42.74%		41.68 - 42.22%
Expected dividend yield		0%		0%		0%
Weighted average grant date fair value		$45.32		$47.84		$50.08

The following table summarizes stock option activity and the weighted average exercise price for the years ended December 31, 2020, 2019 and 2018:

				*Weighted-*
				*Average*
	*Stock Options*			*Exercise Price*

Options outstanding at January 1, 2018		399,055		$	51.13
Granted		36,600			110.59
Exercised		(155,765	)		38.92
Cancelled		(27,274	)		74.35
Options outstanding at December 31, 2018		252,616			64.71
Granted		53,708			105.81
Exercised		(16,079	)		48.67
Cancelled		(13,979	)		89.50
Options outstanding at December 31, 2019		276,266			72.38
Granted		60,065			105.79
Exercised		(68,958	)		57.00
Cancelled		(37,842	)		67.92
Options outstanding at December 31, 2020		229,531		$	86.46

Exercisable at December 31, 2020		94,318		$	69.36

The outstanding options have a term of 10 years. For employees, options that have been granted become exercisable ratably over the vesting period, which is generally a four- or five-year period, beginning on the first anniversary of the grant date, subject to the employee’s continuing service to the Company. For directors, options generally become exercisable in full on the first anniversary of the grant date.

The total intrinsic value of options exercised during the years ended December 31, 2020, 2019 and 2018, was $5.4 million, $0.9 million and $13.0 million, respectively. The aggregate intrinsic value represents the cumulative difference between the fair market value of the underlying common stock and the option exercise prices.

For options outstanding at December 31, 2020, the weighted-average remaining contractual term was 6.8 years and the aggregate intrinsic value was $15.4 million. For options exercisable at December 31, 2020, the weighted-average remaining contractual term was 5.0 years and the aggregate intrinsic value was $7.9 million. Refer to the table below for additional information.

The following table summarizes information about stock options outstanding at December 31, 2020:

	Options Outstanding, Vested and Expected to Vest			Options Exercisable
Range of Exercise Prices	Number Outstanding	Weighted Average Remaining Contractual Life	Weighted Average Exercise Price ($)	Number Exercisable	Weighted Average Exercise Price ($)

$7.76 to $31.43	5,964	1.35	30.58	5,964	30.58
$31.44 to $66.87	78,482	4.81	57.51	56,032	57.18
$66.88 to $96.20	10,591	4.42	74.05	9,343	71.09
$96.21 to $123.10	134,494	8.45	106.81	22,979	108.41

The fair value of share-based payment transactions is recognized in the consolidated statements of comprehensive income. As of December 31, 2020, there was $4.2 million of total unrecognized compensation cost related to unvested stock options, which is expected to be recognized over a weighted average period of 2.6 years. The total fair value of options vested was $1.8 million, $1.5 million and $1.5 million for the years ended December 31, 2020, 2019 and 2018, respectively.

Restricted Stock

The 2012 Plan provides for the award of restricted stock or restricted stock units. Restricted stock awards are share settled and restrictions lapse ratably over the vesting period, which is generally a four- or five-year period, beginning on the first anniversary of the grant date, subject to the employee’s continuing service to the Company. For directors, restrictions generally lapse in full on the first anniversary of the grant date.

The following table summarizes restricted stock activity for the years ended December 31, 2020, 2019 and 2018:

				*Weighted-*
				*Average*
				*Grant Date*
	*Restricted*			*Fair Value*
	*Stock Awards*			*Per Share*

Restricted stock at January 1, 2018		334,831		$	63.29
Granted		106,855			115.41
Restrictions lapsed		(86,191	)		63.64
Forfeited		(31,574	)		68.67
Restricted stock at December 31, 2018		323,921			79.85
Granted		115,471			106.35
Restrictions lapsed		(92,597	)		77.25
Forfeited		(31,822	)		87.58
Restricted stock at December 31, 2019		314,973			89.55
Granted		108,179			111.76
Restrictions lapsed		(101,941	)		84.70
Forfeited		(14,012	)		94.24
Restricted stock at December 31, 2020		307,199		$	98.87

As of December 31, 2020, there was $21.2 million of unrecognized compensation expense related to non-vested restricted stock, which is expected to be recognized over a weighted-average period of 2.4 years.

Performance Stock

Performance Stock Units (PSUs) are expressed in terms of a target number of PSUs, with anywhere between 0 percent and 150 percent of that target number capable of being earned and vesting at the end of a three-year performance period depending on the Company’s performance in the final year of the performance period and the award recipient’s continued employment.

The following table summarizes performance stock activity for the years ended December 31, 2020, 2019 and 2018:

				*Weighted-*
				*Average*
				*Grant Date*
	*Performance*			*Fair Value*
	*Stock Awards*			*Per Share*

Performance stock at January 1, 2018		25,707		$	58.35
Granted		20,006			105.75
Restrictions lapsed		-			-
Performance change		6,427			58.35
Forfeited		-			-
Performance stock at December 31, 2018		52,140			76.54
Granted		21,434			104.99
Restrictions lapsed		-			-
Performance change		(61,816	)		88.06
Forfeited		(2,375	)		105.37
Performance stock at December 31, 2019		9,383			58.35
Granted		19,956			118.66
Restrictions lapsed		(7,113	)		58.35
Performance change		-			-
Forfeited		(2,270	)		58.35
Performance stock at December 31, 2020		19,956		$	118.66

As of December 31, 2020, there was $1.7 million of unrecognized compensation expense related to non-vested performance stock, which is expected to be recognized over a weighted-average period of 2.1 years. Unrecognized stock-based compensation costs related to non-vested performance stock in 2020 when compared to 2019 increased $1.6 million driven by an increase in the number of shares expected to vest at the end of future performance periods.

Employee Stock Purchase Plan

The following table presents the assumptions used to estimate the fair value of the ESPP during the years ended December 31, 2020, 2019 and 2018:

	*Year Ended December 31,*
	*2020*	*2019*	*2018*

Risk-free interest rate	0.12 - 0.17%	1.59 - 2.35%	2.06 - 2.33%
Expected life (months)	6.00	6.00	6.00
Expected volatility	50.85 - 59.99%	42.63 - 53.57%	31.50 - 37.36%
Expected dividend yield	0%	0%	0%

Note 13 - Leases

12 Months Ended

Dec. 31, 2020

Lessee, Operating Leases and Financing Leases [Text Block]

Note 13 – Leases

The Company accounts for leases in accordance with ASC 842, Leases. The Company has operating leases for office space, manufacturing facilities and certain company vehicles and equipment and finance leases for certain company equipment. The leases have remaining lease terms of one year to eight years. Leases with an initial term of 12 months or less are not recorded on the balance sheet; we recognize lease expense for these leases on a straight-line basis over the lease term. For purposes of calculating operating lease liabilities, lease terms may be deemed to include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. As of December 31, 2020, the operating lease liability does not include any options to extend or terminate leases.

The Company determines if an arrangement is a lease at inception. Operating leases are included in operating lease assets, current operating lease liabilities and long-term operating lease liabilities in the Consolidated Balance Sheets and are recognized based on the present value of lease payments over the lease term at commencement date. Finance leases are included in finance lease assets, current finance lease liabilities and long-term finance lease liabilities in the Consolidated Balance Sheets and are recognized based on the present value of lease payments over the lease term at commencement date. The majority of the Company’s leases do not provide an implicit rate of return, therefore, the Company uses its incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. Lease agreements that contain non-lease components, with the exception of certain real estate leases, are accounted for as a single lease component.

Supplemental balance sheet information related to leases was as follows:

	*December 31,*
(in thousands)	*2020*		*2019*
Operating lease assets	$	9,855	$	11,425

Current operating lease liabilities	$	3,272	$	3,340
Long-term operating lease liabilities		7,586		8,565
Total operating lease liabilities	$	10,858	$	11,905


Finance lease assets	$	2,396	$	-

Current finance lease liabilities	$	552	$	-
Long-term finance lease liabilities		1,919		-
Total finance lease liabilities	$	2,471	$	-

Lease expense is recognized on a straight-line basis over the lease term, with variable payments recognized in the period those payments are incurred. The components of lease expense for the periods reported were as follows:

	Twelve Months Ended December 31,
(in thousands)	2020		2019
Operating lease cost	$	4,191	$	3,960
Finance lease cost:
Amortization of right-of-use assets	$	143	$	-
Interest on lease obligations	$	2	$	-
Variable lease cost		989		1,039
Total lease cost	$	5,325	$	4,999

Maturities of operating and finance lease liabilities as of December 31, 2020 were as follows:

(in thousands)	*Operating Leases*			*Finance Leases*
Year Ending December 31,
2021	$	3,915		$	561
2022		3,246			561
2023		1,460			1,371
2024		540			-
2025		494			-
After 2025		1,751			-
Total future minimum lease payments		11,406			2,493
Less interest		(548	)		(22	)
Present value of lease liabilities	$	10,858		$	2,471

As of December 31, 2020, we have no operating or finance leases that have not yet commenced.

Weighted average remaining lease term and discount rate was as follows:

	December 31,
	2020			2019
Weighted Average Remaining Lease Term - operating leases (years)		4.4			4.8
Weighted Average Remaining Lease Term - finance leases (years)		2.5			-
Weighted Average Discount Rate - operating leases		2.6	%		2.6	%
Weighted Average Discount Rate - finance leases		0.5	%		-

Supplemental cash flow information related to leases was as follows:

	*Twelve Months Ended December 31,*
(in thousands)	*2020*		*2019*
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$	4,426	$	5,020
Operating cash flows from finance leases	$	2	$	-
Financing cash flows from finance leases	$	154	$	-

Lease assets obtained in exchange for new operating lease liabilities		1,506		1,921
Lease assets obtained in exchange for new financing lease liabilities		2,523		-

Note 14 - Accumulated Other Comprehensive Loss

12 Months Ended

Dec. 31, 2020

Disclosure of Reclassification Amount [Text Block]

Note 14 – Accumulated Other Comprehensive Loss

Other comprehensive loss is comprised entirely of foreign currency translation adjustments. The following table presents the changes in accumulated other comprehensive loss balances for the years ending December 31, 2020, 2019 and 2018, respectively:

	*Year Ended December 31,*
(in thousands)	*2020*			*2019*			*2018*

Foreign currency translation adjustments
Balance at beginning of period	$	(7,018	)	$	(8,492	)	$	(5,234	)
Other comprehensive (loss) income before reclassifications		3,598			1,474			(3,258	)
Amounts reclassified from accumulated other comprehensive income (loss)		-			-			-
Net current-period other comprehensive (loss) income		3,598			1,474			(3,258	)
Balance at end of period	$	(3,420	)	$	(7,018	)	$	(8,492	)

Note 15 - Income Taxes

12 Months Ended

Dec. 31, 2020

Income Tax Disclosure [Text Block]

Note 15 – Income Taxes

The Company is subject to income tax in multiple jurisdictions and the use of estimates is required to determine the provision for income taxes. For the years ended December 31, 2020, 2019 and 2018, the Company recorded an income tax provision of $12.1 million, $17.5 million and $15.1 million, respectively. The effective income tax rate for the years ended December 31, 2020, 2019 and 2018 was 19.2 percent, 21.6 percent and 16.4 percent, respectively.

The effective tax rate decreased by 2.4% for the year ended December 31, 2020 when compared to 2019 primarily due to an increase in tax benefits from the vesting of restricted stock and exercise of stock options and an increase in the research and development tax credit.

The Tax Cuts and Jobs Act (the “Act”) was enacted on December 22, 2017. The Act reduced the U.S. federal corporate tax rate from 35% to 21%, required companies to pay a transition tax on earnings of certain foreign subsidiaries that were previously tax deferred and creates new taxes on certain foreign sourced earnings. No additional income taxes have been provided for any remaining undistributed foreign earnings not subject to the transition tax, or any additional outside basis difference inherent in these entities, as these amounts continue to be indefinitely reinvested in foreign operations.

The Coronavirus Aid, Relief, and Economic Security (CARES) Act was signed into law on March 27, 2020. The CARES Act was meant to infuse companies with various income and payroll tax cash benefits to ease the impact of the pandemic. A technical correction to the Tax Cuts and Jobs Act of 2017 was included in the CARES Act allowing qualified improvement property to claim bonus depreciation for respective assets placed in service in 2018 and 2019. The impact of the CARES Act to the Company was a $2.9 million reduction to income taxes payable and a corresponding increase to deferred tax liability. In addition, the Company has elected to defer deposits of the employer portion of the Social Security tax for the quarter ended March 31, 2020 through the quarter ended December 31, 2020. The Social Security taxes are being accrued for and will be paid in 2021.

The provision for income taxes is based on income before income taxes reported for financial statement purposes. The components of income before income taxes are as follows:

	*Year Ended December 31,*
(in thousands)	*2020*		*2019*		*2018*

Domestic	$	58,551	$	74,841	$	81,893
Foreign		4,394		6,352		9,762
Total	$	62,945	$	81,193	$	91,655

Significant components of the provision for income taxes for the following periods are as follows:

	*Year Ended December 31,*
(in thousands)	*2020*			*2019*			*2018*

Current:
Federal	$	2,128		$	6,991		$	(782	)
State		1,136			2,882			2,078
Foreign		1,241			1,544			1,810
Deferred
Federal		6,904			5,121			11,325
State		(431	)		269			538
Foreign		210			(809	)		(430	)
Valuation Allowance		890			1,540			528
Total	$	12,078		$	17,538		$	15,067

A reconciliation of the federal statutory income tax rate to the effective tax rate is as follows:

	*Year Ended December 31,*
	*2020*			*2019*			*2018*

Federal tax statutory rate		21.0	%		21.0	%		21.0	%
State tax (net of federal benefit)		2.1			2.1			2.0
Share based compensation		(1.3	)		(0.5	)		(2.8	)
Valuation allowance against deferred tax assets		2.0			1.4			0.7
Research and development credit		(3.7	)		(2.8	)		(2.5	)
Foreign rate differential		(0.8	)		(0.3	)		(0.1	)
Tax reserves		1.4			1.1			(0.1	)
Provision to return difference		(1.4	)		-			-
Miscellaneous		(0.1	)		(0.4	)		(0.5	)
Transition tax		-			-			(0.8	)
Revaluation of deferred tax liability		-			-			(0.5	)
Total		19.2	%		21.6	%		16.4	%

Significant components of deferred tax assets and liabilities are as follows:

	*December 31,*
(in thousands)	*2020*			*2019*

Deferred tax assets:
Accrued expenses	$	2,155		$	1,362
Leases		3,598			3,337
Stock-based compensation		3,356			3,325
Intangible assets		1,693			1,171
Inventories		172			169
Other assets		1,790			1,765
Net operating loss		6,647			6,513
Less valuation allowance		(9,138	)		(8,248	)
Total deferred tax assets		10,273			9,394
Deferred tax liabilities:
Depreciation		(32,671	)		(26,750	)
Goodwill		(7,858	)		(5,590	)
Leases		(3,598	)		(3,337	)
Total deferred tax liabilities		(44,127	)		(35,677	)
Net deferred tax liability	$	(33,854	)	$	(26,283	)

The Company has recorded no U.S. deferred taxes related to the undistributed earnings of its non-U.S. subsidiaries as of December 31, 2020. Such amounts are intended to be reinvested outside of the United States indefinitely. It is not practicable to estimate the amount of additional tax that might be payable on the foreign earnings. As of December 31, 2020, the Company had accumulated undistributed earnings in non-U.S. subsidiaries of $15.8 million.

As of December 31, 2020, the Company had estimated net operating loss carry forwards of $6.6 million for tax purposes. The net operating losses relate to operations in Japan and Germany. Japan losses can be carried forward for up to ten years. The remaining Japan net operating losses begin to expire at various dates between 2021 and 2026. The Company’s Japan operations are taxed both by local authorities and in the U.S. Germany net operating losses may be carried forward without any time limitations but are limited to €1 million, plus 60 percent of taxable income exceeding €1 million.

The Company establishes valuation allowances for deferred tax assets when, after consideration of all positive and negative evidence, it is considered more-likely-than-not that a portion of the deferred tax assets will not be realized. The Company's valuation allowances of $9.1 million and $8.2 million at December 31, 2020 and 2019, respectively, reduce the carrying value of deferred tax assets associated with certain net operating loss carry forwards and other assets with insufficient positive evidence for recognition. The increase in the valuation allowance is primarily attributable to fluctuations in foreign currency and the net operating losses incurred in Germany in 2020.

The Company files a U.S. federal income tax return and income tax returns in various states and foreign jurisdictions. With a few exceptions, the Company is no longer subject to U.S. federal, state, or foreign income tax examinations by tax authorities for years before 2017.

The Company has liabilities related to unrecognized tax benefits totaling $4.8 million and $4.6 million at December 31, 2020 and 2019, respectively, that if recognized would result in a reduction of the Company’s effective tax rate. The liabilities are classified as other long-term liabilities in the accompanying consolidated balance sheets. The Company recognizes interest and penalties related to income tax matters in income tax expense and reports the liability in current or long-term income taxes payable as appropriate. Interest and penalties were immaterial for each of the years ended December 31, 2020, 2019 and 2018.

A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows:

	*December 31,*
	*2020*			*2019*

Balance at beginning of period	$	4,598		$	4,096
Additions for tax positions of current year		324			592
Additions for tax positions of prior years		475			-
Decrease related to expiration of statutes of limitations		(567	)		(90	)
Balance at period end	$	4,830		$	4,598

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

Note 16 - Litigation

12 Months Ended

Dec. 31, 2020

Legal Matters and Contingencies [Text Block]

Note 16 – Litigation

From time to time, the Company may be subject to various legal proceedings and claims that arise in the ordinary course of its business. Although the results of litigation and claims cannot be predicted with certainty, the Company does not believe it is a party to any litigation the outcome of which, if determined adversely, would individually or in the aggregate be reasonably expected to have a material adverse effect on its business.

Note 17 - Segment Reporting

12 Months Ended

Dec. 31, 2020

Segment Reporting Disclosure [Text Block]

Note 17 – Segment Reporting

The Company’s reportable segments are based on the internal reporting used by the Company’s CEO, who is the chief operating decision maker (CODM), to assess operating performance and make decisions about the allocation of resources. The Company’s reportable segments are based upon geographic region, consisting of the United States and Europe. The Corporate Unallocated and Japan category includes non-reportable segments, as well as research and development and general and administrative costs that are global in nature and that the Company does not allocate directly to its operating segments.

Revenue in the United States is derived from Injection Molding, CNC Machining, 3D Printing and Sheet Metal product lines. Revenue in Europe is derived from Injection Molding, CNC Machining, and 3D Printing product lines. Revenue in Japan is derived from Injection Molding and CNC Machining product lines. Injection Molding revenue consists of sales of custom injection molds and injection-molded parts. CNC Machining revenue consists of sales of CNC-machined and lathe-turned customer parts. 3D Printing revenue consists of sales of 3D-printed parts. Sheet Metal revenue consists of sales of fabricated sheet metal parts.

The accounting policies of the reportable segments are the same as those described in Note 2 – Summary of Significant Accounting Policies. Intercompany transactions primarily relate to intercontinental activity and have been eliminated and are excluded from the reported amounts. The difference between income from operations and pre-tax income relates to foreign currency-related gains and losses and interest income on cash balances and investments, which are not allocated to business segments.

Beginning in 2020, the Company's CODM made a decision to view certain research and development costs by geographic region. As a result, costs previously included in the Corporate Unallocated and Japan category have been included in the respective geographic regions. All periods presented have been restated to reflect this change.

Revenue and income from operations by reportable segment are as follows:

	*Year Ended December 31,*
(in thousands)	*2020*		*2019*		*2018*
Revenue:
United States	$	345,708	$	360,205	$	350,535
Europe		74,796		82,805		80,889
Japan		13,891		15,718		14,172
Total revenue	$	434,395	$	458,728	$	445,596

	*Year Ended December 31,*
(in thousands)	*2020*			*2019*			*2018*
Income from Operations:
United States	$	98,762		$	108,594		$	115,710
Europe		11,707			15,077			16,747
Corporate Unallocated and Japan		(50,633	)		(43,815	)		(43,557	)
Total income from operations	$	59,836		$	79,856		$	88,898

Total long-lived assets, expenditures for additions to long-lived assets and depreciation and amortization expense are as follows:

	*December 31,*		*December 31,*		*December 31,*
(in thousands)	*2020*		*2019*		*2018*
Long-lived assets:
United States	$	215,721	$	210,171	$	185,979
Europe		59,388		45,019		34,577
Japan		7,557		8,522		7,445
Total long-lived assets	$	282,666	$	263,712	$	228,001

	*Year Ended December 31,*
(in thousands)	*2020*		*2019*		*2018*
Expenditures for additions to long-lived assets:
United States	$	29,984	$	45,123	$	78,762
Europe		16,574		14,743		7,576
Japan		452		2,364		766
Total expenditures for additions to long-lived assets	$	47,010	$	62,230	$	87,104

Year Ended December 31,

(in thousands)

2020

2019

2018

Depreciation and Amortization:

United States
$ 25,744 $ 24,767 $ 21,117

Europe
5,024 4,746 4,679

Japan
1,826 1,351 958

Total depreciation and amortization
$ 32,594 $ 30,864 $ 26,754

The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments.

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Note 18 - Subsequent Events

12 Months Ended

Dec. 31, 2020

Subsequent Events [Text Block]

Note 18 – Subsequent Events

On January 22, 2021, the Company acquired 3D Hubs, Inc. (“3D Hubs”), for $294.4 million, consisting of $127.7 million in cash and 863,995 shares of the Company's common stock valued at $166.7 million on the date of close. Up to an additional $52.8 million of contingent consideration is payable subject to the satisfaction of performance-based targets during fiscal year 2021 and fiscal year 2022 after closing, consisting of up to $25.0 million in cash and up to 143,983 shares of the Company's common stock valued at $27.8 million on the date of close. 3D Hubs is a leading online manufacturing platform that provides customers with on-demand access to a global network of approximately 240 premium manufacturing partners. The completion of this transaction creates the world’s most comprehensive digital manufacturing offer for custom parts. The acquisition will be accounted for under the acquisition method of accounting in accordance with ASC 805.

On February 3, 2021, the Company announced the launch of its new digital quoting and design analysis platform to its U.S.-based customers, following a launch in the fourth quarter of 2020 to its European-based users. With the launch, three of the Company's services—injection molding, CNC machining, and 3D printing—are now united in a single platform for a much easier quoting and ordering experience. The advanced e-commerce system is built to accelerate online quoting, design analysis and ordering.

Significant Accounting Policies (Policies)	12 Months Ended
Significant Accounting Policies (Policies)	Dec. 31, 2020
Accounting Policies [Abstract]
Consolidation, Policy [Policy Text Block]	Principles of consolidation The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries, as listed within “Organization and business” above. All intercompany accounts and transactions have been eliminated in consolidation.
Comprehensive Income, Policy [Policy Text Block]	Comprehensive income Components of comprehensive income include net income and foreign currency translation adjustments. Comprehensive income is disclosed in the accompanying consolidated statements of comprehensive income and consolidated statements of shareholders’ equity.
Use of Estimates, Policy [Policy Text Block]	Accounting estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America (U.S. GAAP) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and related disclosures at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Cash and Cash Equivalents, Policy [Policy Text Block]	Cash and cash equivalents Cash and cash equivalents include cash and other investments, including marketable securities, with maturities of three months or less at the date of purchase. The Company maintains its cash in bank deposit accounts, which, at times, may exceed federally insured limits. The Company has not experienced any losses on such accounts.
Marketable Securities, Policy [Policy Text Block]	Marketable securities Marketable securities include held-to-maturity debt securities recorded at amortized cost. Management determines the appropriate classification of debt securities at the time of purchase and reevaluates such designation as of each balance sheet date. Debt securities are classified as held-to-maturity when the Company has the positive intent and ability to hold the securities to maturity. Held-to-maturity securities are stated at amortized cost, adjusted for amortization of premiums and accretion of discounts to maturity computed under the effective interest method. Such amortization is included in other income, net. Interest on securities classified as held to maturity is included in other income, net. The classification of marketable securities as current or non-current is dependent upon the security’s maturity date. Securities with maturities of three months or less at the time of purchase are categorized as cash equivalents as described above. During the first quarter of 2020, the Company adopted the FASB ASU 2016-13, Financial Instruments – Credit Losses. The Company calculated the expected credit loss for each security in its portfolio using the probability-of-default method. The Company concluded the adoption of the guidance had no material impact on its consolidated financial statements.
Accounts Receivable [Policy Text Block]	Accounts receivable and allowance for doubtful accounts Accounts receivable are reported at the invoiced amount less an allowance for doubtful accounts. As of each balance sheet date, the Company evaluates its accounts receivable and establishes an allowance for doubtful accounts based on a combination of specific customer circumstances and credit conditions taking into account the history of write-offs and collections. A receivable is considered past due if payment has not been received within the period agreed upon in the invoice. Accounts receivable are written off after all collection efforts have been exhausted. Recoveries of trade receivables previously written off are recorded when received.
Inventory, Policy [Policy Text Block]	Inventory Inventory consists primarily of raw materials, which are recorded at the lower of cost or market, using the average cost method, which approximates first-in, first-out (FIFO) cost. The Company periodically reviews its inventory for slow-moving, damaged and discontinued items and provides allowances to reduce such items identified to their recoverable amounts.
Property, Plant and Equipment, Policy [Policy Text Block]	Property, equipment and leasehold improvements Property, equipment and leasehold improvements are stated at cost. Major improvements that substantially extend an asset’s useful life are capitalized. Repairs, maintenance and minor improvements are charged to operations as incurred. Depreciation, including amortization of leasehold improvements and assets recorded under capital leases, is calculated using the straight-line method over the estimated useful lives of the individual assets and ranges from 3 to 39 years. Manufacturing equipment is depreciated over 3 to 15 years, office furniture and equipment are depreciated over 3 to 7 years, computer hardware and software are depreciated over 3 to 5 years, building costs are depreciated over 39 years, leasehold improvements are depreciated over the estimated lives of the related assets or the life of the lease, whichever is shorter, and building and land improvements are depreciated over 10 to 39 years. Assets not in service are not depreciated until the asset is put into use. The Company follows ASC 350-40, Internal-Use Software, in accounting for internally developed software. As of December 31, 2020 and 2019, respectively, $49.4 million and $32.7 million of software development costs were capitalized. Capitalized software development costs for the year ended December 31, 2020 were $16.7 million.
Goodwill and Intangible Assets, Goodwill, Policy [Policy Text Block]	Goodwill The Company recognizes goodwill in accordance with ASC 350, Intangibles—Goodwill and Other. Goodwill is the excess of cost of an acquired entity over the amounts assigned to assets acquired and liabilities assumed in a business combination. Goodwill is not amortized. Goodwill is tested for impairment annually in the fourth quarter of each year, and is tested for impairment between annual tests if an event occurs or circumstances change that would indicate the carrying amount may be impaired. An impairment charge for goodwill is recognized only when the estimated fair value of a reporting unit, including goodwill, is less than its carrying amount. In 2020, the Company performed a qualitative analysis based on the significance of the fair value over the carrying value in prior period assessments. As of December 31, 2020, no impairment charges for goodwill have been recognized.
Internal Use Software, Policy [Policy Text Block]	Capitalized Software Costs The Company follows ASC 350-40, Intangibles – Goodwill and Other, Internal-Use Software, in accounting for internally developed software. Costs for internal use software are evaluated by projected and capitalized where appropriate.
Goodwill and Intangible Assets, Intangible Assets, Policy [Policy Text Block]	Other Intangible Assets Other intangible assets include software technology, customer relationships and other intangible assets acquired from other independent parties. Other intangible assets with a definite life are amortized over a period ranging from two to 10 years on a straight line basis, and are tested for impairment whenever events or circumstances indicate that the carrying amount of an asset (asset group) may not be recoverable. An impairment loss is recognized when the carrying amount of an asset exceeds the estimated undiscounted cash flows generated by the asset. The amount of the impairment loss recorded is calculated by the excess of the asset’s carrying value over its fair value.
Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block]	Accounting for long-lived assets The Company periodically reviews the carrying amount of its property, equipment and leasehold improvements to determine if circumstances exist indicating an impairment or if depreciation periods should be modified. If facts or circumstances indicate that an impairment may exist, the Company will prepare a projection of the undiscounted future cash flows of the specific assets to determine if the assets are recoverable. If impairment exists based on these projections, an adjustment will be made to reduce the carrying amount of the specific assets to fair value.
Revenue [Policy Text Block]	Revenue recognition The Company recognizes revenue in accordance with ASC 606, Revenue from Contracts with Customers. The Company manufactures custom parts to specific customer orders that have no alternative use to the Company, and the Company believes there is a legally enforceable right to payment for performance completed to date on these manufactured parts. For manufactured parts that meet these two criteria, the Company will recognize revenue over time. Revenue is recognized over time using the input method based on time in production as a percentage of total estimated production time to measure progress toward satisfying performance obligations using the estimated total time necessary to complete the parts per the customer's order and an estimate of inventory and production costs incurred to date. The majority of the Company’s injection molding contracts have multiple performance obligations including one obligation to produce the mold and a second obligation to produce parts. For injection molding contracts with multiple performance obligations, the Company allocates revenue to each performance obligation based on its relative standalone selling price. The Company generally determines standalone selling price based on the price charged to customers.
Lessee, Leases [Policy Text Block]	Leases The Company accounts for leases in accordance with ASC 842, Leases, which requires the balance sheet recognition of lease assets and lease liabilities by lessees for those leases classified as operating and finance leases. The Company determines if an arrangement is a lease at inception. Operating and finance leases are included in operating and finance lease assets, current operating and finance lease liabilities and long-term operating and finance lease liabilities in the Consolidated Balance Sheets and are recognized based on the present value of lease payments over the lease term at commencement date.
Income Tax, Policy [Policy Text Block]	Income taxes The Company accounts for income taxes in accordance with ASC 740, Income Taxes (ASC 740). Under this method, the Company determines tax assets and liabilities based upon the differences between the financial statement carrying amounts and the tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to affect taxable income. The tax consequences of most events recognized in the financial statements are included in determining income taxes currently payable. However, because tax laws and financial accounting standards differ in their recognition and measurement of assets, liabilities and equity, revenues, expenses, gains and losses, differences arise between the amount of taxable income and pretax financial income for a year and between the tax basis of assets or liabilities and their reported amounts in the financial statements. Because the Company assumes that the reported amounts of assets and liabilities will be recovered and settled, respectively, a difference between the tax basis of an asset or liability and its reported amount in the balance sheet will result in a taxable or a deductible amount in some future years when the related liabilities are settled or the reported amounts of the assets are recovered, giving rise to a deferred tax asset or liability. The Company establishes a valuation allowance for any portion of its deferred tax assets that the Company believes may not be recognized. ASC 740 also clarifies the accounting for uncertainty in income taxes recognized in an enterprise’s financial statements by requiring that individual tax positions are recorded only when they meet a more-likely-than-not criterion. The Company recognizes the effect of income tax positions only if sustaining those positions is more likely than not. The Company records penalties and interest related to unrecognized tax benefits in income taxes in the Company’s Consolidated Statements of Income.
Compensation Related Costs, Policy [Policy Text Block]	Stock-based compensation The Company accounts for stock-based compensation in accordance with ASC 718, Compensation—Stock Compensation (ASC 718). Under the fair value recognition provisions of ASC 718, the Company measures stock-based compensation cost at the grant date fair value and recognizes the compensation expense over the requisite service period, which is the vesting period, using a straight-line attribution method. The amount of stock-based compensation expense recognized during a period is based on the portion of the awards that are ultimately expected to vest. The Company accounts for forfeitures as they occur. Ultimately, the total expense recognized over the vesting period will only be for those awards that vest. The Company’s awards are not eligible to vest early in the event of retirement, however, the awards vest early in the event of a change in control. In determining the compensation cost of the options granted, the fair value of options granted has been estimated on the date of grant using the Black-Scholes option-pricing model.
Advertising Cost [Policy Text Block]	Advertising costs Advertising is expensed as incurred and was approximately $11.5 million, $13.0 million and $11.8 million for the years ended December 31, 2020, 2019 and 2018, respectively.
Research and Development Expense, Policy [Policy Text Block]	Research and development Research and development expenses consist primarily of personnel and outside service costs related to the development of new processes and product lines, enhancements of existing product lines, development of software for internal use, maintenance of internally developed software, quality assurance and testing. Costs for internal use software are evaluated by project and capitalized where appropriate under ASC 350-40, Intangibles - Goodwill and Other, Internal-Use Software. Research and development costs were approximately $36.9 million, $32.7 million and $28.7 million for the years ended December 31, 2020, 2019 and 2018, respectively.
Foreign Currency Transactions and Translations Policy [Policy Text Block]	Foreign currency translation/transactions The Company translated the balance sheets of its foreign subsidiaries at period-end exchange rates and the income statement at the average exchange rates in effect throughout the period. The Company has recorded the translation adjustment as a separate component of consolidated shareholders’ equity. Foreign currency transaction gains and losses are recognized in the consolidated statements of comprehensive income.
New Accounting Pronouncements, Policy [Policy Text Block]	Recently adopted accounting pronouncements During the first quarter of 2020, the Company adopted the Financial Accounting Standards Board (FASB) Accounting Standards Update (ASU) 2016-13, Financial Instruments – Credit Losses, which is intended to provide financial statement users with more decision-useful information about the expected credit losses on financial instruments held by a reporting entity at each reporting date. The adoption of this guidance had no material impact on our consolidated financial statements. During the first quarter of 2019, the Company adopted the FASB ASU 2016-02, Leases (ASC 842), which introduces the balance sheet recognition of lease assets and lease liabilities by lessees for those leases classified as operating leases under previous guidance. The Company has adopted the new lease standard using the new transition option issued under the amendments in ASU 2018-11, Leases, which allowed the Company to continue to apply the legacy guidance in Accounting Standards Codification (ASC) 840, Leases, in the comparative periods presented in the year of adoption. The Company elected the package of practical expedients permitted under the transition guidance within the new standard, which among other things, allowed the Company to carry forward the historical lease classification. The Company made an accounting policy election to keep leases with an initial term of 12 months or less off of the balance sheet. The Company will recognize those lease payments in the Consolidated Statements of Comprehensive Income on a straight-line basis over the lease term. The impact of the adoption was an increase to the Company’s operating lease assets and liabilities on January 1, 2019 of $13.1 million. Recently issued accounting pronouncements In December 2019, the FASB issued ASU 2019-12, Income Taxes, which is intended to simplify the accounting for income taxes. This guidance will be effective for fiscal years beginning after December 15, 2020 and interim periods within those fiscal years with early adoption permitted. The Company is evaluating the impact of future adoption of this guidance on its consolidated financial statements, but does not expect the impact to be material.

Note 3 - Revenue (Tables)

12 Months Ended

Dec. 31, 2020

Disaggregation of Revenue [Table Text Block]

	*Year Ended December 31,*
(in thousands)	*2020*		*2019*		*2018*
Revenue:
United States	$	345,708	$	360,205	$	350,535
Europe		74,796		82,805		80,889
Japan		13,891		15,718		14,172
Total revenue	$	434,395	$	458,728	$	445,596

	*Year Ended December 31,*
(in thousands)	*2020*		*2019*		*2018*
Revenue:
Injection Molding	$	217,992	$	217,415	$	210,523
CNC Machining		131,587		155,473		153,521
3D Printing		62,502		61,352		53,342
Sheet Metal		18,838		21,000		24,998
Other Revenue		3,476		3,488		3,212
Total revenue	$	434,395	$	458,728	$	445,596

Note 4 - Net Income Per Common Share (Tables)

12 Months Ended

Dec. 31, 2020

Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]

	*Year Ended December 31,*
(in thousands, except share and per share amounts)	*2020*		*2019*		*2018*

Net Income	$	50,867	$	63,655	$	76,588

Basic - weighted-average shares outstanding:		26,737,425		26,866,985		26,982,614
Effect of dilutive securities:
Employee stock options and other		158,932		182,438		296,202
Diluted - weighted-average shares outstanding:		26,896,357		27,049,423		27,278,816
Net income per share attributable to common shareholders:
Basic	$	1.90	$	2.37	$	2.84
Diluted	$	1.89	$	2.35	$	2.81

Note 5 - Goodwill and Other Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2020

Schedule of Goodwill [Table Text Block]

(in thousands)	*Dec. 31, 2018*		*Goodwill acquired during 2019*		*Dec. 31, 2019*		*Goodwill acquired during 2020*		*Dec. 31, 2020*

United States	$	123,883	$	-	$	123,883	$	-	$	123,883
Europe		4,239		-		4,239		-		4,239
Japan		630		-		630		-		630
Total goodwill	$	128,752	$	-	$	128,752	$	-	$	128,752

Schedule of Finite-Lived Intangible Assets [Table Text Block]

	*Year Ended December 31, 2020*							*Year Ended December 31, 2019*								*Weighted Average Useful Life*
(in thousands)	*Gross*		*Accumulated Amortization*			*Net*		*Gross*		*Accumulated Amortization*			*Net*		*Useful Life (in years)*	*Remaining (in years)*
Intangible Assets with finite lives:
Marketing assets	$930		$(620		)	$310		$930		$(527		)	$403		10.0	3.3
Non-compete agreement	270		(238		)	32		270		(222		)	48		2.0 - 5.0	2.3
Software technology	13,229		(3,645		)	9,584		13,229		(2,275		)	10,954		10.0	7.3
Customer relationships	10,070		(5,646		)	4,424		10,070		(4,106		)	5,964		6.0 - 9.0	2.8
Total intangible assets	$	24,499	$	(10,149	)	$	14,350	$	25,829	$	(8,460	)	$	17,369

Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]

(in thousands)	*Estimated Amortization Expense*
2021	$	3,016
2022		3,016
2023		2,813
2024		1,400
2025		1,369
Thereafter		2,736
Total estimated amortization expense	$	14,350

Note 6 - Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2020

Fair Value, Assets Measured on Recurring Basis [Table Text Block]

	*December 31, 2020*						*December 31, 2019*
(in thousands)	*Level 1*		*Level 2*		*Level 3*		*Level 1*		*Level 2*		*Level 3*

Financial Assets:
Cash and cash equivalents
Money market mutual funds	$	55,378	$	-	$	-	$	68,962	$	-	$	-
Total	$	55,378	$	-	$	-	$	68,962	$	-	$	-

Note 7 - Marketable Securities (Tables)

12 Months Ended

Dec. 31, 2020

Debt Securities, Held-to-maturity [Table Text Block]

	*December 31, 2020*
(in thousands)	*Amortized Cost*		*Unrealized Gains*		*Unrealized Losses*			*Fair Value*

U.S. government agency securities	$	18,500	$	6	$	(10	)	$	18,496
Corporate debt securities		42,048		211		(11	)		42,248
U.S. municipal securities		25,003		83		(2	)		25,084
Commercial paper		2,499		-		-			2,499
Certificates of deposit/time deposits		5,395		93		-			5,488
Total marketable securities	$	93,445	$	393	$	(23	)	$	93,815

	*December 31, 2019*
(in thousands)	*Amortized Cost*		*Unrealized Gains*		*Unrealized Losses*			*Fair Value*

U.S. government agency securities	$	6,274	$	1	$	(7	)	$	6,268
Corporate debt securities		26,944		80		(12	)		27,012
U.S. municipal securities		10,204		9		(3	)		10,210
Commercial paper		3,491		-		-			3,491
Certificates of deposit/time deposits		1,484		22		-			1,506
Total marketable securities	$	48,397	$	112	$	(22	)	$	48,487

Investments Classified by Contractual Maturity Date [Table Text Block]

	*December 31,*
(in thousands)	*2020*

Due in one year or less	$	34,088
Due after one year through five years		59,357
Total marketable securities	$	93,445

Note 8 - Property and Equipment (Tables)

12 Months Ended

Dec. 31, 2020

Property, Plant and Equipment [Table Text Block]

	*December 31,*
(in thousands)	*2020*			*2019*

Land	$	14,028		$	14,098
Buildings and improvements		77,285			75,843
Machinery and equipment		221,301			208,954
Computer hardware and software		79,207			24,953
Leasehold improvements		7,821			7,341
Construction in progress		33,780			54,313
Total		433,422			385,502
Accumulated depreciation and amortization		(150,756	)		(121,790	)
Property and equipment, net	$	282,666		$	263,712

Note 9 - Inventory (Tables)

12 Months Ended

Dec. 31, 2020

Schedule of Inventory, Current [Table Text Block]

	*December 31,*
(in thousands)	*2020*			*2019*

Total inventory		11,122			10,319
Allowance for obsolescence		(260	)		(244	)
Inventory, net of allowance	$	10,862		$	10,075

Note 12 - Stock-based Compensation (Tables)

12 Months Ended

Dec. 31, 2020

Share-based Payment Arrangement, Cost by Plan [Table Text Block]

	*Year Ended December 31,*
(in thousands)	*2020*		*2019*		*2018*

Stock options and other	$	13,327	$	9,591	$	10,113
Employee stock purchase plan		1,346		1,190		815
Total stock-based compensation expense	$	14,673	$	10,781	$	10,928

Cost of revenue	$	2,451	$	2,056	$	1,543
Operating expenses:
Marketing and sales		3,121		2,632		1,942
Research and development		2,440		1,851		1,517
General and administrative		6,661		4,242		5,926
Total stock-based compensation expense	$	14,673	$	10,781	$	10,928

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

	*Year Ended December 31,*
	*2020*		*2019*		*2018*

Risk-free interest rate		0.50 - 1.47%		2.35 - 2.58%		2.52 - 3.07%
Expected life (years)		6.25		6.25		6.25
Expected volatility		42.40 - 43.83%		42.52 - 42.74%		41.68 - 42.22%
Expected dividend yield		0%		0%		0%
Weighted average grant date fair value		$45.32		$47.84		$50.08

Share-based Payment Arrangement, Option, Activity [Table Text Block]

				*Weighted-*
				*Average*
	*Stock Options*			*Exercise Price*

Options outstanding at January 1, 2018		399,055		$	51.13
Granted		36,600			110.59
Exercised		(155,765	)		38.92
Cancelled		(27,274	)		74.35
Options outstanding at December 31, 2018		252,616			64.71
Granted		53,708			105.81
Exercised		(16,079	)		48.67
Cancelled		(13,979	)		89.50
Options outstanding at December 31, 2019		276,266			72.38
Granted		60,065			105.79
Exercised		(68,958	)		57.00
Cancelled		(37,842	)		67.92
Options outstanding at December 31, 2020		229,531		$	86.46

Exercisable at December 31, 2020		94,318		$	69.36

Share-based Payment Arrangement, Option, Exercise Price Range [Table Text Block]

	Options Outstanding, Vested and Expected to Vest			Options Exercisable
Range of Exercise Prices	Number Outstanding	Weighted Average Remaining Contractual Life	Weighted Average Exercise Price ($)	Number Exercisable	Weighted Average Exercise Price ($)

$7.76 to $31.43	5,964	1.35	30.58	5,964	30.58
$31.44 to $66.87	78,482	4.81	57.51	56,032	57.18
$66.88 to $96.20	10,591	4.42	74.05	9,343	71.09
$96.21 to $123.10	134,494	8.45	106.81	22,979	108.41

Share-based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity [Table Text Block]

				*Weighted-*
				*Average*
				*Grant Date*
	*Restricted*			*Fair Value*
	*Stock Awards*			*Per Share*

Restricted stock at January 1, 2018		334,831		$	63.29
Granted		106,855			115.41
Restrictions lapsed		(86,191	)		63.64
Forfeited		(31,574	)		68.67
Restricted stock at December 31, 2018		323,921			79.85
Granted		115,471			106.35
Restrictions lapsed		(92,597	)		77.25
Forfeited		(31,822	)		87.58
Restricted stock at December 31, 2019		314,973			89.55
Granted		108,179			111.76
Restrictions lapsed		(101,941	)		84.70
Forfeited		(14,012	)		94.24
Restricted stock at December 31, 2020		307,199		$	98.87

Schedule of Nonvested Performance-based Units Activity [Table Text Block]

				*Weighted-*
				*Average*
				*Grant Date*
	*Performance*			*Fair Value*
	*Stock Awards*			*Per Share*

Performance stock at January 1, 2018		25,707		$	58.35
Granted		20,006			105.75
Restrictions lapsed		-			-
Performance change		6,427			58.35
Forfeited		-			-
Performance stock at December 31, 2018		52,140			76.54
Granted		21,434			104.99
Restrictions lapsed		-			-
Performance change		(61,816	)		88.06
Forfeited		(2,375	)		105.37
Performance stock at December 31, 2019		9,383			58.35
Granted		19,956			118.66
Restrictions lapsed		(7,113	)		58.35
Performance change		-			-
Forfeited		(2,270	)		58.35
Performance stock at December 31, 2020		19,956		$	118.66

Schedule of Share-based Payment Award, Awards Other Than Stock Options, Valuation Assumptions [Table Text Block]

	*Year Ended December 31,*
	*2020*	*2019*	*2018*

Risk-free interest rate	0.12 - 0.17%	1.59 - 2.35%	2.06 - 2.33%
Expected life (months)	6.00	6.00	6.00
Expected volatility	50.85 - 59.99%	42.63 - 53.57%	31.50 - 37.36%
Expected dividend yield	0%	0%	0%

Note 13 - Leases (Tables)

12 Months Ended

Dec. 31, 2020

Assets and Liabilities, Lessee [Table Text Block]

	*December 31,*
(in thousands)	*2020*		*2019*
Operating lease assets	$	9,855	$	11,425

Current operating lease liabilities	$	3,272	$	3,340
Long-term operating lease liabilities		7,586		8,565
Total operating lease liabilities	$	10,858	$	11,905


Finance lease assets	$	2,396	$	-

Current finance lease liabilities	$	552	$	-
Long-term finance lease liabilities		1,919		-
Total finance lease liabilities	$	2,471	$	-

Schedule of Lease Expense [Table Text Block]

	Twelve Months Ended December 31,
(in thousands)	2020		2019
Operating lease cost	$	4,191	$	3,960
Finance lease cost:
Amortization of right-of-use assets	$	143	$	-
Interest on lease obligations	$	2	$	-
Variable lease cost		989		1,039
Total lease cost	$	5,325	$	4,999

	*Twelve Months Ended December 31,*
(in thousands)	*2020*		*2019*
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$	4,426	$	5,020
Operating cash flows from finance leases	$	2	$	-
Financing cash flows from finance leases	$	154	$	-

Lease assets obtained in exchange for new operating lease liabilities		1,506		1,921
Lease assets obtained in exchange for new financing lease liabilities		2,523		-

Lessee, Lease Liability, Maturity [Table Text Block]

(in thousands)	*Operating Leases*			*Finance Leases*
Year Ending December 31,
2021	$	3,915		$	561
2022		3,246			561
2023		1,460			1,371
2024		540			-
2025		494			-
After 2025		1,751			-
Total future minimum lease payments		11,406			2,493
Less interest		(548	)		(22	)
Present value of lease liabilities	$	10,858		$	2,471

Schedule of Lease Terms and Discount Rates [Table Text Block]

	December 31,
	2020			2019
Weighted Average Remaining Lease Term - operating leases (years)		4.4			4.8
Weighted Average Remaining Lease Term - finance leases (years)		2.5			-
Weighted Average Discount Rate - operating leases		2.6	%		2.6	%
Weighted Average Discount Rate - finance leases		0.5	%		-

Note 14 - Accumulated Other Comprehensive Loss (Tables)

12 Months Ended

Dec. 31, 2020

Comprehensive Income (Loss) [Table Text Block]

	*Year Ended December 31,*
(in thousands)	*2020*			*2019*			*2018*

Foreign currency translation adjustments
Balance at beginning of period	$	(7,018	)	$	(8,492	)	$	(5,234	)
Other comprehensive (loss) income before reclassifications		3,598			1,474			(3,258	)
Amounts reclassified from accumulated other comprehensive income (loss)		-			-			-
Net current-period other comprehensive (loss) income		3,598			1,474			(3,258	)
Balance at end of period	$	(3,420	)	$	(7,018	)	$	(8,492	)

Note 15 - Income Taxes (Tables)

12 Months Ended

Dec. 31, 2020

Schedule of Income before Income Tax, Domestic and Foreign [Table Text Block]

	*Year Ended December 31,*
(in thousands)	*2020*		*2019*		*2018*

Domestic	$	58,551	$	74,841	$	81,893
Foreign		4,394		6,352		9,762
Total	$	62,945	$	81,193	$	91,655

Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]

	*Year Ended December 31,*
(in thousands)	*2020*			*2019*			*2018*

Current:
Federal	$	2,128		$	6,991		$	(782	)
State		1,136			2,882			2,078
Foreign		1,241			1,544			1,810
Deferred
Federal		6,904			5,121			11,325
State		(431	)		269			538
Foreign		210			(809	)		(430	)
Valuation Allowance		890			1,540			528
Total	$	12,078		$	17,538		$	15,067

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

	*Year Ended December 31,*
	*2020*			*2019*			*2018*

Federal tax statutory rate		21.0	%		21.0	%		21.0	%
State tax (net of federal benefit)		2.1			2.1			2.0
Share based compensation		(1.3	)		(0.5	)		(2.8	)
Valuation allowance against deferred tax assets		2.0			1.4			0.7
Research and development credit		(3.7	)		(2.8	)		(2.5	)
Foreign rate differential		(0.8	)		(0.3	)		(0.1	)
Tax reserves		1.4			1.1			(0.1	)
Provision to return difference		(1.4	)		-			-
Miscellaneous		(0.1	)		(0.4	)		(0.5	)
Transition tax		-			-			(0.8	)
Revaluation of deferred tax liability		-			-			(0.5	)
Total		19.2	%		21.6	%		16.4	%

Schedule of Deferred Tax Assets and Liabilities [Table Text Block]

	*December 31,*
(in thousands)	*2020*			*2019*

Deferred tax assets:
Accrued expenses	$	2,155		$	1,362
Leases		3,598			3,337
Stock-based compensation		3,356			3,325
Intangible assets		1,693			1,171
Inventories		172			169
Other assets		1,790			1,765
Net operating loss		6,647			6,513
Less valuation allowance		(9,138	)		(8,248	)
Total deferred tax assets		10,273			9,394
Deferred tax liabilities:
Depreciation		(32,671	)		(26,750	)
Goodwill		(7,858	)		(5,590	)
Leases		(3,598	)		(3,337	)
Total deferred tax liabilities		(44,127	)		(35,677	)
Net deferred tax liability	$	(33,854	)	$	(26,283	)

Schedule of Unrecognized Tax Benefits Roll Forward [Table Text Block]

	*December 31,*
	*2020*			*2019*

Balance at beginning of period	$	4,598		$	4,096
Additions for tax positions of current year		324			592
Additions for tax positions of prior years		475			-
Decrease related to expiration of statutes of limitations		(567	)		(90	)
Balance at period end	$	4,830		$	4,598

Note 17 - Segment Reporting (Tables)

12 Months Ended

Dec. 31, 2020

Income from Operations by Geographic Area [Table Text Block]

	*Year Ended December 31,*
(in thousands)	*2020*			*2019*			*2018*
Income from Operations:
United States	$	98,762		$	108,594		$	115,710
Europe		11,707			15,077			16,747
Corporate Unallocated and Japan		(50,633	)		(43,815	)		(43,557	)
Total income from operations	$	59,836		$	79,856		$	88,898

Long-lived Assets by Geographic Areas [Table Text Block]

	*December 31,*		*December 31,*		*December 31,*
(in thousands)	*2020*		*2019*		*2018*
Long-lived assets:
United States	$	215,721	$	210,171	$	185,979
Europe		59,388		45,019		34,577
Japan		7,557		8,522		7,445
Total long-lived assets	$	282,666	$	263,712	$	228,001

Expenditures for Additions to Long-lived Assets by Geographic Region [Table Text Block]

	*Year Ended December 31,*
(in thousands)	*2020*		*2019*		*2018*
Expenditures for additions to long-lived assets:
United States	$	29,984	$	45,123	$	78,762
Europe		16,574		14,743		7,576
Japan		452		2,364		766
Total expenditures for additions to long-lived assets	$	47,010	$	62,230	$	87,104

Depreciation and Amortization by Geographic Region [Table Text Block]

	*Year Ended December 31,*
(in thousands)	*2020*		*2019*		*2018*
Depreciation and Amortization:
United States	$	25,744	$	24,767	$	21,117
Europe		5,024		4,746		4,679
Japan		1,826		1,351		958
Total depreciation and amortization	$	32,594	$	30,864	$	26,754

Operating Segments [Member]

Revenue from External Customers by Geographic Areas [Table Text Block]

	*Year Ended December 31,*
(in thousands)	*2020*		*2019*		*2018*
Revenue:
United States	$	345,708	$	360,205	$	350,535
Europe		74,796		82,805		80,889
Japan		13,891		15,718		14,172
Total revenue	$	434,395	$	458,728	$	445,596

Note 2 - Summary of Significant Accounting Policies (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Jan. 01, 2019
Capitalized Computer Software, Net, Ending Balance	$ 49,400	$ 32,700	$ 16,700
Goodwill, Impairment Loss	0
Advertising Expense	11,500	13,000	11,800
Research and Development Expense, Total	36,940	32,692	$ 28,735
Operating Lease, Right-of-Use Asset	9,855	11,425
Operating Lease, Liability, Total	$ 10,858	$ 11,905
Accounting Standards Update 2016-02 [Member]
Operating Lease, Right-of-Use Asset				$ 13,100
Building [Member]
Property, Plant and Equipment, Useful Life (Year)	39 years
Minimum [Member]
Property, Plant and Equipment, Useful Life (Year)	3 years
Finite-Lived Intangible Asset, Useful Life (Year)	2 years
Minimum [Member] \| Equipment [Member]
Property, Plant and Equipment, Useful Life (Year)	3 years
Minimum [Member] \| Office Furniture And Equipment [Member]
Property, Plant and Equipment, Useful Life (Year)	3 years
Minimum [Member] \| Computer Equipment [Member]
Property, Plant and Equipment, Useful Life (Year)	3 years
Minimum [Member] \| Land, Buildings and Improvements [Member]
Property, Plant and Equipment, Useful Life (Year)	10 years
Maximum [Member]
Property, Plant and Equipment, Useful Life (Year)	39 years
Finite-Lived Intangible Asset, Useful Life (Year)	10 years
Maximum [Member] \| Equipment [Member]
Property, Plant and Equipment, Useful Life (Year)	15 years
Maximum [Member] \| Office Furniture And Equipment [Member]
Property, Plant and Equipment, Useful Life (Year)	7 years
Maximum [Member] \| Computer Equipment [Member]
Property, Plant and Equipment, Useful Life (Year)	5 years
Maximum [Member] \| Land, Buildings and Improvements [Member]
Property, Plant and Equipment, Useful Life (Year)	39 years

Note 3 - Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue:
Revenue	$ 434,395	$ 458,728	$ 445,596
Injection Molding (Protomold) [Member]
Revenue:
Revenue	217,992	217,415	210,523
CNC Machining (Firstcut) [Member]
Revenue:
Revenue	131,587	155,473	153,521
3D Printing (Fineline) [Member]
Revenue:
Revenue	62,502	61,352	53,342
Sheet Metal [Member]
Revenue:
Revenue	18,838	21,000	24,998
Other Products [Member]
Revenue:
Revenue	3,476	3,488	3,212
UNITED STATES
Revenue:
Revenue	345,708	360,205	350,535
Europe [Member]
Revenue:
Revenue	74,796	82,805	80,889
JAPAN
Revenue:
Revenue	$ 13,891	$ 15,718	$ 14,172

Note 4 - Net Income Per Common Share - Computation of Basic and Diluted Net Income Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Net income	$ 50,867	$ 63,655	$ 76,588
Basic - weighted-average shares outstanding: (in shares)	26,737,425	26,866,985	26,982,614
Employee stock options and other (in shares)	158,932	182,438	296,202
Diluted - weighted-average shares outstanding: (in shares)	26,896,357	27,049,423	27,278,816
Basic (in dollars per share)	$ 1.90	$ 2.37	$ 2.84
Diluted (in dollars per share)	$ 1.89	$ 2.35	$ 2.81

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Note 5 - Goodwill and Other Intangible Assets (Details Textual) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Amortization of Intangible Assets, Total	$ 3.0	$ 3.5	$ 3.2

Note 5 - Goodwill and Other Intangible Assets - Changes in Carrying Amount of Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Goodwill, balance as of the beginning of the period	$ 128,752	$ 128,752
Goodwill acquired during the period	0	0
Goodwill, balance as of the end of the period	128,752	128,752
UNITED STATES
Goodwill, balance as of the beginning of the period	123,883	123,883
Goodwill acquired during the period	0	0
Goodwill, balance as of the end of the period	123,883	123,883
Europe [Member]
Goodwill, balance as of the beginning of the period	4,239	4,239
Goodwill acquired during the period	0	0
Goodwill, balance as of the end of the period	4,239	4,239
JAPAN
Goodwill, balance as of the beginning of the period	630	630
Goodwill acquired during the period	0	0
Goodwill, balance as of the end of the period	$ 630	$ 630

Note 5 - Goodwill and Other Intangible Assets - Intangible Assets Other Than Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Gross	$ 24,499	$ 25,829
Accumulated Amortization	(10,149)	(8,460)
Net	$ 14,350	17,369
Minimum [Member]
Useful Life (Year)	2 years
Maximum [Member]
Useful Life (Year)	10 years
Marketing-Related Intangible Assets [Member]
Gross	$ 930	930
Accumulated Amortization	620	527
Net	$ 310	403
Useful Life (Year)	10 years
Weighted average useful life remaining (Year)	3 years 3 months 18 days
Noncompete Agreements [Member]
Gross	$ 270	270
Accumulated Amortization	(238)	(222)
Net	$ 32	48
Weighted average useful life remaining (Year)	2 years 3 months 18 days
Noncompete Agreements [Member] \| Minimum [Member]
Useful Life (Year)	2 years
Noncompete Agreements [Member] \| Maximum [Member]
Useful Life (Year)	5 years
Computer Software, Intangible Asset [Member]
Gross	$ 13,229	13,229
Accumulated Amortization	(3,645)	(2,275)
Net	$ 9,584	10,954
Useful Life (Year)	10 years
Weighted average useful life remaining (Year)	7 years 3 months 18 days
Customer Relationships [Member]
Gross	$ 10,070	10,070
Accumulated Amortization	(5,646)	(4,106)
Net	$ 4,424	$ 5,964
Weighted average useful life remaining (Year)	2 years 9 months 18 days
Customer Relationships [Member] \| Minimum [Member]
Useful Life (Year)	6 years
Customer Relationships [Member] \| Maximum [Member]
Useful Life (Year)	9 years

Note 5 - Goodwill and Other Intangible Assets - Estimated Aggregated Amortization Expense (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
2021	$ 3,016
2022	3,016
2023	2,813
2024	1,400
2025	1,369
Thereafter	2,736
Total estimated amortization expense	$ 14,350	$ 17,369

Note 6 - Fair Value Measurements - Fair Value of Financial Assets Measured on a Recurring Basis (Details) - Fair Value, Recurring [Member] - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Inputs, Level 1 [Member]
Money market mutual funds	$ 55,378	$ 68,962
Total	55,378	68,962
Fair Value, Inputs, Level 2 [Member]
Money market mutual funds	0	0
Total	0	0
Fair Value, Inputs, Level 3 [Member]
Money market mutual funds	0	0
Total	$ 0	$ 0

Note 7 - Marketable Securities - Short-term and Long-term Marketable Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Amortized Cost	$ 93,445	$ 48,397
Unrealized Gains	393	112
Unrealized Losses	(23)	(22)
Fair Value	93,815	48,487
Bank Time Deposits [Member]
Amortized Cost	5,395	1,484
Unrealized Gains	93	22
Unrealized Losses	0	0
Fair Value	5,488	1,506
US Government Agencies Debt Securities [Member]
Amortized Cost	18,500	6,274
Unrealized Gains	6	1
Unrealized Losses	(10)	(7)
Fair Value	18,496	6,268
Corporate Debt Securities [Member]
Amortized Cost	42,048	26,944
Unrealized Gains	211	80
Unrealized Losses	(11)	(12)
Fair Value	42,248	27,012
US States and Political Subdivisions Debt Securities [Member]
Amortized Cost	25,003	10,204
Unrealized Gains	83	9
Unrealized Losses	(2)	(3)
Fair Value	25,084	10,210
Commercial Paper, Not Included with Cash and Cash Equivalents [Member]
Amortized Cost	2,499	3,491
Unrealized Gains	0	0
Unrealized Losses	0	0
Fair Value	$ 2,499	$ 3,491

Note 7 - Marketable Securities - Balance of Held-to-maturity Debt Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Due in one year or less	$ 34,088
Due after one year through five years	59,357
Total marketable securities	$ 93,445	$ 48,397

Note 8 - Property and Equipment (Details Textual) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Depreciation, Total	$ 29.6	$ 27.4	$ 23.5

Note 8 - Property and Equipment - Components of Property and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Land	$ 14,028	$ 14,098
Buildings and improvements	77,285	75,843
Machinery and equipment	221,301	208,954
Computer hardware and software	79,207	24,953
Leasehold improvements	7,821	7,341
Construction in progress	33,780	54,313
Total	433,422	385,502
Accumulated depreciation and amortization	(150,756)	(121,790)
Property and equipment, net	$ 282,666	$ 263,712	$ 228,001

Note 9 - Inventory - Inventory (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Total inventory	$ 11,122	$ 10,319
Allowance for obsolescence	(260)	(244)
Inventory, net of allowance	$ 10,862	$ 10,075

Note 10 - Financing Obligations (Details Textual) $ in Thousands	Dec. 31, 2020 USD ($)
Long-term Line of Credit, Total	$ 0

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

Note 11 - Employee Benefit Plans (Details Textual) - 401(k) Retirement Plan [Member] $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
UNITED STATES
Minimum Number Of Employee Working Hours Required To Be Eligible To Participate In 401K Plan	20
Minimum Service Period Of Employees To Avail Benefit Under Defined Contribution Benefit Plan (Month)	3 months
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent	50.00%
Defined Contribution Plan, Employer Discretionary Contribution Amount	$ 3.3	$ 3.1	$ 2.7
Foreign Plan [Member]
Defined Contribution Plan, Employer Discretionary Contribution Amount	$ 0.5	$ 0.3	$ 0.3

Note 12 - Stock-based Compensation (Details Textual) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value	$ 5.4	$ 0.9	$ 13.0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term (Year)	6 years 9 months 18 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value	$ 15.4
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term (Year)	5 years
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value	$ 7.9
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value	$ 1.8	$ 1.5	$ 1.5
ESPP [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Discount from Market Price, Offering Date	15.00%
Employee Stock Purchase Plan, Offering Period (Month)	6 months
Share-based Compensation Arrangement by Share-based Payment Award, Purchase Price of Common Stock, Percent	85.00%
Shares Issued, Shares, Share-based Payment Arrangement, after Forfeiture, Total (in shares)	42,235	41,615
Employee Stock Purchase Plan, Weighted Average Purchase Price of Shares Purchased (in shares)	85.85	86.70
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant (in shares)	1,126,595
Share-based Payment Arrangement, Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year)	10 years
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total	$ 4.2
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)	2 years 7 months 6 days
Share-based Payment Arrangement, Option [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)	4 years
Share-based Payment Arrangement, Option [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)	5 years
Restricted Stock [Member]
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total	$ 21.2
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)	2 years 4 months 24 days
Restricted Stock [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)	4 years
Restricted Stock [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)	5 years
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)	3 years
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total	$ 1.7
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)	2 years 1 month 6 days
Percentage of Target Number Capable of Being Earned and Vesting, Lower Limit	0.00%
Percentage of Target Number Capable of Being Earned and Vesting, Upper Limit	150.00%
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Change in Amount	$ 1.6
Long-Term Incentive Plan 2012 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year)	10 years

Note 12 - Stock-based Compensation - Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Allocated share-based compensation expense	$ 14,673	$ 10,781	$ 10,928
Cost of Sales [Member]
Allocated share-based compensation expense	2,451	2,056	1,543
Selling and Marketing Expense [Member]
Allocated share-based compensation expense	3,121	2,632	1,942
Research and Development Expense [Member]
Allocated share-based compensation expense	2,440	1,851	1,517
General and Administrative Expense [Member]
Allocated share-based compensation expense	6,661	4,242	5,926
Stock Options, Restricted Stock, and Other [Member]
Allocated share-based compensation expense	13,327	9,591	10,113
ESPP [Member]
Allocated share-based compensation expense	$ 1,346	$ 1,190	$ 815

Note 12 - Stock-based Compensation - Assumptions Used in the Black-Scholes Option Pricing Model (Details) - Share-based Payment Arrangement, Option [Member] - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Expected life (Year)	6 years 3 months	6 years 3 months	6 years 3 months
Expected dividend yield	0.00%	0.00%	0.00%
Weighted average grant date fair value (in dollars per share)	$ 45.32	$ 47.84	$ 50.08
Minimum [Member]
Risk-free interest rate	0.50%	2.35%	2.52%
Expected volatility	42.40%	42.52%	41.68%
Maximum [Member]
Risk-free interest rate	1.47%	2.58%	3.07%
Expected volatility	43.83%	42.74%	42.22%

Note 12 - Stock-based Compensation - Stock Option Activity (Details) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Options outstanding (in shares)	276,266	252,616	399,055
Options outstanding, weighted-average exercise price (in dollars per share)	$ 72.38	$ 64.71	$ 51.13
Granted (in shares)	60,065	53,708	36,600
Granted, weighted-average exercise price (in dollars per share)	$ 105.79	$ 105.81	$ 110.59
Exercised (in shares)	(68,958)	(16,079)	(155,765)
Exercised, weighted-average exercise price (in dollars per share)	$ 57.00	$ 48.67	$ 38.92
Cancelled (in shares)	(37,842)	(13,979)	(27,274)
Cancelled, weighted-average exercise price (in dollars per share)	$ 67.92	$ 89.50	$ 74.35
Options outstanding (in shares)	229,531	276,266	252,616
Options outstanding, weighted-average exercise price (in dollars per share)	$ 86.46	$ 72.38	$ 64.71
Options exercisable (in shares)	94,318
Options exercisable, weighted-average exercise price (in dollars per share)	$ 69.36

Note 12 - Stock-based Compensation - Information about Stock Options Outstanding (Details) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Options outstanding, vested and expected to vest, number outstanding (in shares)	229,531	276,266	252,616	399,055
Options outstanding, vested and expected to vest, weighted average exercise price (in dollars per share)	$ 86.46	$ 72.38	$ 64.71	$ 51.13
Exercise Price Range One [Member]
Range of exercise prices, lower limit (in dollars per share)
Options outstanding, vested and expected to vest, number outstanding (in shares)	5,964
Range of exercise prices, upper limit (in dollars per share)
Options outstanding, vested and expected to vest, weighted average remaining contractual life (Year)	1 year 4 months 6 days
Options outstanding, vested and expected to vest, weighted average exercise price (in dollars per share)	$ 30.58
Options exercisable, number exercisable (in shares)	5,964
Options exercisable, weighted average exercise price (in dollars per share)	$ 30.58
Exercise Price Range Two [Member]
Range of exercise prices, lower limit (in dollars per share)
Options outstanding, vested and expected to vest, number outstanding (in shares)	78,482
Range of exercise prices, upper limit (in dollars per share)
Options outstanding, vested and expected to vest, weighted average remaining contractual life (Year)	4 years 9 months 21 days
Options outstanding, vested and expected to vest, weighted average exercise price (in dollars per share)	$ 57.51
Options exercisable, number exercisable (in shares)	56,032
Options exercisable, weighted average exercise price (in dollars per share)	$ 57.18
Exercise Price Range Three [Member]
Range of exercise prices, lower limit (in dollars per share)
Options outstanding, vested and expected to vest, number outstanding (in shares)	10,591
Range of exercise prices, upper limit (in dollars per share)
Options outstanding, vested and expected to vest, weighted average remaining contractual life (Year)	4 years 5 months 1 day
Options outstanding, vested and expected to vest, weighted average exercise price (in dollars per share)	$ 74.05
Options exercisable, number exercisable (in shares)	9,343
Options exercisable, weighted average exercise price (in dollars per share)	$ 71.09
Exercise Price Range Four [Member]
Range of exercise prices, lower limit (in dollars per share)
Options outstanding, vested and expected to vest, number outstanding (in shares)	134,494
Range of exercise prices, upper limit (in dollars per share)
Options outstanding, vested and expected to vest, weighted average remaining contractual life (Year)	8 years 5 months 12 days
Options outstanding, vested and expected to vest, weighted average exercise price (in dollars per share)	$ 106.81
Options exercisable, number exercisable (in shares)	22,979
Options exercisable, weighted average exercise price (in dollars per share)	$ 108.41

Note 12 - Stock-based Compensation - Restricted Stock Options (Details) - Restricted Stock [Member] - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Restricted stock (in shares)	314,973	323,921	334,831
Restricted stock, weighted-average grant date fair value (in dollars per share)	$ 89.55	$ 79.85	$ 63.29
Granted (in shares)	108,179	115,471	106,855
Granted, weighted-average grant date fair value (in dollars per share)	$ 111.76	$ 106.35	$ 115.41
Restrictions lapsed (in shares)	(101,941)	(92,597)	(86,191)
Restrictions lapsed, weighted-average grant date fair value (in dollars per share)	$ 84.70	$ 77.25	$ 63.64
Forfeited (in shares)	(14,012)	(31,822)	(31,574)
Forfeited, weighted-average grant date fair value (in dollars per share)	$ 94.24	$ 87.58	$ 68.67
Restricted stock (in shares)	307,199	314,973	323,921
Restricted stock, weighted-average grant date fair value (in dollars per share)	$ 98.87	$ 89.55	$ 79.85

Note 12 - Stock-based Compensation - Performance Stock (Details) - Performance Shares [Member] - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Performance stock (in shares)	9,383	52,140	25,707
Restricted stock, weighted-average grant date fair value (in dollars per share)	$ 58.35	$ 76.54	$ 58.35
Granted (in shares)	19,956	21,434	20,006
Granted, weighted-average grant date fair value (in dollars per share)	$ 118.66	$ 104.99	$ 105.75
Restrictions lapsed (in shares)	(7,113)	0	0
Restrictions lapsed, weighted-average grant date fair value (in dollars per share)	$ 58.35	$ 0	$ 0
Performance change (in shares)	0	(61,816)	6,427
Performance change, weighted-average grant date fair value (in dollars per share)	$ 0	$ 88.06	$ 58.35
Forfeited (in shares)	(2,270)	(2,375)	0
Forfeited, weighted-average grant date fair value (in dollars per share)	$ 58.35	$ 105.37	$ 0
Granted (in shares)	19,956	21,434	20,006
Restrictions lapsed (in shares)	7,113	0	(0)
Performance change, weighted-average grant date fair value (in dollars per share)	$ 0	$ 88.06	$ 58.35
Forfeited (in shares)	(2,270)	(2,375)	0
Restrictions lapsed (in shares)	(7,113)	0	0
Performance stock (in shares)	19,956	9,383	52,140
Restricted stock, weighted-average grant date fair value (in dollars per share)	$ 118.66	$ 58.35	$ 76.54

Note 12 - Stock-based Compensation - Assumptions Used in the Valuation of Performance Stock (Details) - Performance Shares [Member]	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Expected life (Year)	6 years	6 years	6 years
Expected dividend yield	0.00%	0.00%	0.00%
Minimum [Member]
Risk-free interest rate	0.12%	1.59%	2.06%
Expected volatility	50.85%	42.63%	31.50%
Maximum [Member]
Risk-free interest rate	0.17%	2.35%	2.33%
Expected volatility	59.99%	53.57%	37.36%

Note 13 - Leases (Details Textual) - Office Space, Manufacturing Facilities, and Certain Company Vehicles and Equipment [Member]	Dec. 31, 2020
Minimum [Member]
Lessee, Operating Lease, Term of Contract (Year)	1 year
Maximum [Member]
Lessee, Operating Lease, Term of Contract (Year)	8 years

Note 13 - Leases - Balance Sheet Information (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Operating lease assets	$ 9,855	$ 11,425
Current operating lease liabilities	3,272	3,340
Long-term operating lease liabilities	7,586	8,565
Total operating lease liabilities	10,858	11,905
Finance lease assets	2,396	0
Current finance lease liabilities	552	0
Long-term finance lease liabilities	1,919	0
Total finance lease liabilities	$ 2,471	$ 0

Note 13 - Leases - Lease Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating lease cost	$ 4,191	$ 3,960
Amortization of right-of-use assets	143	0
Interest on lease obligations	2	0
Variable lease cost	989	1,039
Total lease cost	5,325	4,999
Operating cash flows from operating leases	4,426	5,020
Operating cash flows from finance leases	2	0
Financing cash flows from finance leases	154	(0)	$ (0)
Lease assets obtained in exchange for new operating lease liabilities	1,506	1,921
Lease assets obtained in exchange for new financing lease liabilities	$ 2,523	$ 0

Note 13 - Leases - Maturities of Operating Lease Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
2021, operating lease	$ 3,915
2021, finance lease	561
2022, operating lease	3,246
2022, finance lease	561
2023, operating lease	1,460
2023, finance lease	1,371
2024, operating lease	540
2024, finance lease	0
2025, operating lease	494
2025, finance lease	0
After 2025, operating lease	1,751
After 2025, finance lease	0
Total future minimum lease payments, operating lease	11,406
Total future minimum lease payments, finance lease	2,493
Less interest, operating lease	(548)
Less interest, finance lease	(22)
Present value of lease liabilities, operating lease	10,858	$ 11,905
Present value of lease liabilities	$ 2,471	$ 0

Note 13 - Leases - Weighted Average Remaining Terms and Discount Rates (Details)	Dec. 31, 2020	Dec. 31, 2019
Weighted Average Remaining Lease Term - operating leases (years) (Year)	4 years 4 months 24 days	4 years 9 months 18 days
Weighted Average Remaining Lease Term - finance leases (years) (Year)	2 years 6 months
Weighted Average Discount Rate - operating leases	2.60%	2.60%
Weighted Average Discount Rate - finance leases	0.50%	0.00%

Note 14 - Accumulated Other Comprehensive Loss - Other Comprehensive Loss (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Balance	$ 585,790	$ 541,497	$ 461,215
Balance	644,356	585,790	541,497
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Balance	(7,018)	(8,492)	(5,234)
Other comprehensive (loss) income before reclassifications	3,598	1,474	(3,258)
Amounts reclassified from accumulated other comprehensive income (loss)	0	0	0
Net current-period other comprehensive (loss) income	3,598	1,474	(3,258)
Balance	$ (3,420)	$ (7,018)	$ (8,492)

Amount after tax and reclassification adjustments of other comprehensive income (loss).

Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

Note 15 - Income Taxes (Details Textual) - USD ($) $ in Thousands		12 Months Ended
	Dec. 22, 2017	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Expense (Benefit), Total		$ 12,078	$ 17,538	$ 15,067
Effective Income Tax Rate Reconciliation, Percent, Total		19.20%	21.60%	16.40%
Effective Income Tax Rate Continuing Operations Increase (Decrease) During the Period		2.40%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	35.00%	21.00%	21.00%	21.00%
Increase (Decrease) in Income Taxes Payable, CARES Act		$ (2,900)
Deferred Tax Liability Not Recognized, Amount of Unrecognized Deferred Tax Liability, Undistributed Earnings of Foreign Subsidiaries		0
Undistributed Earnings of Foreign Subsidiaries		15,800
Operating Loss Carryforwards, Total		$ 6,600
Operating Loss Carryforwards, Expiration Period (Year)		10 years
Operating Loss Carryforwards, Percentage of Taxable Income		60.00%
Deferred Tax Assets, Valuation Allowance, Total		$ 9,138	$ 8,248
Unrecognized Tax Benefits, Ending Balance		4,830	$ 4,598	$ 4,096
Deferred Tax Liability, CARES Act		$ 2,900

Note 15 - Income Taxes - Components of Income (Loss) Before Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Domestic	$ 58,551	$ 74,841	$ 81,893
Foreign	4,394	6,352	9,762
Income before income taxes	$ 62,945	$ 81,193	$ 91,655

Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest.

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Note 15 - Income Taxes - Significant Components of Provision for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current:
Federal	$ 2,128	$ 6,991	$ (782)
State	1,136	2,882	2,078
Foreign	1,241	1,544	1,810
Deferred
Federal	6,904	5,121	11,325
State	(431)	269	538
Foreign	210	(809)	(430)
Valuation Allowance	890	1,540	528
Total	$ 12,078	$ 17,538	$ 15,067

Note 15 - Income Taxes - Reconciliation of Federal Statutory Income Tax Rate to Effective Tax Rate (Details)		12 Months Ended
	Dec. 22, 2017	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Federal tax statutory rate	35.00%	21.00%	21.00%	21.00%
State tax (net of federal benefit)		2.10%	2.10%	2.00%
Share based compensation		(1.30%)	(0.50%)	(2.80%)
Valuation allowance against deferred tax assets		2.00%	1.40%	0.70%
Research and development credit		(3.70%)	(2.80%)	(2.50%)
Foreign rate differential		(0.80%)	(0.30%)	(0.10%)
Tax reserves		1.40%	1.10%	(0.10%)
Provision to return difference		(1.40%)	0.00%	0.00%
Miscellaneous		(0.10%)	(0.40%)	(0.50%)
Transition tax		0.00%	0.00%	(0.80%)
Revaluation of deferred tax liability		0.00%	0.00%	(0.50%)
Total		19.20%	21.60%	16.40%

Note 15 - Income Taxes - Significant Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Accrued expenses	$ 2,155	$ 1,362
Leases	3,598	3,337
Stock-based compensation	3,356	3,325
Intangible assets	1,693	1,171
Inventories	172	169
Other assets	1,790	1,765
Net operating loss	6,647	6,513
Less valuation allowance	(9,138)	(8,248)
Total deferred tax assets	10,273	9,394
Deferred tax liabilities:
Depreciation	(32,671)	(26,750)
Goodwill	(7,858)	(5,590)
Leases	(3,598)	(3,337)
Total deferred tax liabilities	(44,127)	(35,677)
Net deferred tax liability	$ (33,854)	$ (26,283)

Note 15 - Income Taxes - Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Balance	$ 4,598	$ 4,096
Additions for tax positions of current year	324	592
Additions for tax positions of prior years	475	0
Decrease related to expiration of statutes of limitations	(567)	(90)
Balance	$ 4,830	$ 4,598

Note 17 - Segment Reporting - Revenue From Operations by Reportable Segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue	$ 434,395	$ 458,728	$ 445,596
Operating Segments [Member]
Revenue	434,395	458,728	445,596
Operating Segments [Member] \| United States Segment [Member]
Revenue	345,708	360,205	350,535
Operating Segments [Member] \| Europe Segment [Member]
Revenue	74,796	82,805	80,889
Operating Segments [Member] \| Japan Segment [Member]
Revenue	$ 13,891	$ 15,718	$ 14,172

Amount, including tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value-added and excise.

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