ExOne (XONE) 10-K 11 Mar 21 2020 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Mar. 09, 2021	Jun. 30, 2020
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Trading Symbol	XONE
Entity Registrant Name	ExOne Co
Entity Central Index Key	0001561627
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		22,073,724
Entity Public Float			$ 100.9
Title of 12(b) Security	Common stock
Security Exchange Name	NASDAQ
Entity File Number	001-35806
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	46-1684608
Entity Address, Address Line One	127 Industry Boulevard
Entity Address, City or Town	North Huntingdon
Entity Address, State or Province	PA
Entity Address, Postal Zip Code	15642
City Area Code	724
Local Phone Number	863-9663
Document Transition Report	false
Entity Interactive Data Current	Yes
Document Annual Report	true
ICFR Auditor Attestation Flag	false
Documents Incorporated by Reference	Portions of the registrant’s definitive proxy statement to be filed pursuant to Regulation 14A of the general rules and regulations under the Securities Exchange Act of 1934, as amended, for its 2021 Annual Meeting of Stockholders are incorporated by reference into Part III of this Annual Report on Form 10-K

Statement of Consolidated Opera

Statement of Consolidated Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Statement [Abstract]
Revenue	$ 59,253	$ 53,276
Cost of sales	44,771	35,848
Gross profit	14,482	17,428
Operating expenses
Research and development	8,845	9,884
Selling, general and administrative	20,953	22,592
Gain from sale-leaseback of property and equipment	(1,462)
Total operating expenses	28,336	32,476
Loss from operations	(13,854)	(15,048)
Other expense
Interest expense	239	343
Other expense ̶ net	631	111
Total other expense (income)	870	454
Loss before income taxes	(14,724)	(15,502)
Provision (benefit) for income taxes	200	(407)
Net loss	$ (14,924)	$ (15,095)
Net loss per common share:
Basic	$ (0.86)	$ (0.93)
Diluted	$ (0.86)	$ (0.93)
Comprehensive loss:
Net loss	$ (14,924)	$ (15,095)
Other comprehensive income (loss):
Comprehensive loss	(13,579)	(15,830)
Foreign currency translation adjustments	$ 1,345	$ (735)

Consolidated Balance Sheet

Consolidated Balance Sheet - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 49,668	$ 5,265
Restricted cash	508	978
Accounts receivable ̶ net	5,225	6,522
Current portion of net investment in sales-type leases ̶ net	229	213
Inventories ̶ net	20,562	19,770
Prepaid expenses and other current assets	4,451	2,182
Total current assets	80,643	34,930
Property and equipment ̶ net	21,300	38,895
Operating lease right-of-use assets	4,043	432
Net investment in sales-type leases ̶ net of current portion ̶ net	509	738
Other noncurrent assets	794	371
Total assets	107,289	75,366
Current liabilities:
Current portion of long-term debt	1,622	153
Current portion of operating lease liabilities	1,958	158
Accounts payable	4,501	5,818
Accrued expenses and other current liabilities	4,978	6,942
Current portion of contract liabilities	13,586	11,846
Total current liabilities	26,645	24,917
Long-term debt ̶ net of current portion	1,783	1,211
Operating lease liabilities ̶ net of current portion	2,085	274
Contract liabilities ̶ net of current portion	159	286
Other noncurrent liabilities	314	96
Total liabilities	30,986	26,784
Contingencies and commitments
Stockholders' equity
Common stock, $0.01 par value, 200,000,000 shares authorized, 20,009,157 (2020) and 16,346,960 (2019) shares issued and outstanding	200	163
Additional paid-in capital	218,113	176,850
Accumulated deficit	(131,872)	(116,948)
Accumulated other comprehensive loss	(10,138)	(11,483)
Total stockholders' equity	76,303	48,582
Total liabilities and stockholders' equity	$ 107,289	$ 75,366

Consolidated Balance Sheet (Par

Consolidated Balance Sheet (Parenthetical) - $ / shares	Dec. 31, 2020	Dec. 31, 2019
Statement Of Financial Position [Abstract]
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	20,009,157	16,346,960
Common stock, shares outstanding	20,009,157	16,346,960

Statement of Consolidated Cash

Statement of Consolidated Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Operating activities
Net loss	$ (14,924)	$ (15,095)
Adjustments to reconcile net loss to net cash used for operations:
Depreciation	3,775	4,581
Equity-based compensation	1,225	1,416
Amortization of debt issuance costs	49	93
Provision for bad debts ̶ net	23	279
Provision for slow-moving, obsolete and lower of cost or net realizable value inventories ̶ net	423	292
Foreign exchange losses on intercompany transactions ̶ net	566	63
Gain from sale-leaseback of property and equipment	(1,462)
Loss (gain) from disposal of property and equipment ̶ net	7	(147)
Deferred income taxes	195	(199)
Changes in assets and liabilities, excluding effects of foreign currency translation adjustments:
Decrease in accounts receivable	1,464	2
Decrease in net investment in sales-type leases	213	269
Increase in inventories	(2,236)	(5,713)
Increase in prepaid expenses and other assets	(2,247)	(632)
(Decrease) increase in accounts payable	(1,679)	1,514
Decrease in accrued expenses and other liabilities	(2)	(1,308)
Increase in contract liabilities	774	9,281
Net cash used for operating activities	(13,836)	(5,304)
Investing activities
Capital expenditures	(1,231)	(666)
Proceeds from sale of property and equipment	16,229	3,186
Net cash provided by investing activities	14,998	2,520
Financing activities
Proceeds from borrowings on long-term debt	2,194
Payments on long-term debt	(158)	(149)
Proceeds from related party revolving credit facility		4,000
Payments on related party revolving credit facility		(4,000)
Proceeds from at-the-market offerings of common stock, net of issuance costs	39,340
Taxes related to the net share settlement of equity-based awards	(28)	(68)
Proceeds from exercise of employee stock options	934	289
Other	(69)	(13)
Net cash provided by financing activities	42,213	59
Effect of exchange rate changes on cash, cash equivalents, and restricted cash	558	(172)
Net change in cash, cash equivalents, and restricted cash	43,933	(2,897)
Cash, cash equivalents, and restricted cash at beginning of period	6,243	9,140
Cash, cash equivalents, and restricted cash at end of period	50,176	6,243
Supplemental disclosure of cash flow information
Cash paid for interest	167	222
Cash paid for income taxes	516	199
Supplemental disclosure of noncash investing and financing activities
Transfer of internally developed 3D printing machines from inventories to property and equipment for internal use or leasing activities	3,524	2,572
Transfer of internally developed 3D printing machines from property and equipment to inventories for sale	1,650	1,206
Property and equipment included in accounts payable	65	$ 71
At-the-market offering issuance costs included in accounts payable	$ 171

Statement of Changes in Consoli

Statement of Changes in Consolidated Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Loss [Member]
Beginning Balance at Dec. 31, 2018	$ 62,775	$ 162	$ 175,214	$ (101,853)	$ (10,748)
Beginning Balance, Shares at Dec. 31, 2018		16,234,000
Net loss	(15,095)			(15,095)
Other comprehensive income (loss)	(735)				(735)
Equity-based compensation	1,416		1,416
Exercise of employee stock options	$ 289	$ 1	288
Exercise of employee stock options, shares	40,432	40,000
Common stock issued from equity incentive plan, shares		73,000
Tax withholding related to the net share settlement of equity-based awards	$ (68)		(68)
Ending Balance at Dec. 31, 2019	$ 48,582	$ 163	176,850	(116,948)	(11,483)
Ending Balance, Shares at Dec. 31, 2019	16,346,960	16,347,000
Net loss	$ (14,924)			(14,924)
Other comprehensive income (loss)	1,345				1,345
Equity-based compensation	1,225	$ 1	1,224
Exercise of employee stock options	$ 934	$ 1	933
Exercise of employee stock options, shares	127,854	128,000
Common stock issued from equity incentive plan, shares		92,000
Tax withholding related to the net share settlement of equity-based awards	$ (28)		(28)
Taxes related to the net share settlement of equity-based awards, shares		(3,000)
At-the-market offerings of common stock,net of issuance costs	39,169	$ 35	39,134
At the market offerings of common stock,net of issuance costs, shares		3,445,000
Ending Balance at Dec. 31, 2020	$ 76,303	$ 200	$ 218,113	$ (131,872)	$ (10,138)
Ending Balance, Shares at Dec. 31, 2020	20,009,157	20,009,000

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Note 1. Summary of Significant Accounting Policies Organization The ExOne Company (“ExOne”) is a corporation organized under the laws of the state of Delaware. ExOne was formed on January 1, 2013, when The Ex One Company, LLC, a Delaware limited liability company, merged with and into a Delaware corporation, which survived and changed its name to The ExOne Company (the “Reorganization”). As a result of the Reorganization, The Ex One Company, LLC became ExOne, the common and preferred interest holders of The Ex One Company, LLC became holders of common stock and preferred stock, respectively, of ExOne, and the subsidiaries of The Ex One Company, LLC became the subsidiaries of ExOne. The consolidated financial statements include the accounts of ExOne, its wholly-owned subsidiaries, ExOne Americas LLC (United States); ExOne GmbH (Germany); ExOne Property GmbH (Germany); and ExOne KK (Japan). Collectively, the consolidated group is referred to as the “Company”. The Company filed a shelf registration statement on Form S-3 (No. 333-223690) with the Securities and Exchange Commission (“SEC”) on March 15, 2018. The purpose of the Form S-3 was to register various equity and debt securities. Subsidiaries of the Company are co-registrants with the Company (“Subsidiary Guarantors”), and the registration statement registered guarantees of debt securities by one or more of the Subsidiary Guarantors. The Subsidiary Guarantors are 100% owned by the Company and any guarantees by the Subsidiary Guarantors will be full and unconditional . Basis of Presentation The consolidated financial statements of the Company are prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). All material intercompany transactions and balances have been eliminated in consolidation. Certain amounts relating to operating lease right-of-use assets ($432), current portion of operating lease liabilities ($158) and operating lease liabilities – net of current portion ($274) in the accompanying consolidated balance sheet at December 31, 2019, have been reclassified from other noncurrent assets, accrued expenses and other current liabilities and other noncurrent liabilities, respectively, to conform to current period presentation. Use of Estimates The preparation of these consolidated financial statements requires the Company to make certain judgments, estimates and assumptions regarding uncertainties that affect the reported amounts of assets, liabilities, revenue and expenses and related disclosure of contingent assets and liabilities. Areas that require significant judgments, estimates and assumptions include accounting for accounts receivable (including the allowance for doubtful accounts); inventories (including the allowance for slow-moving and obsolete inventories); product warranty reserves; contingencies; revenue (including the allocation of a sales contract’s total transaction price to each performance obligation for contracts with multiple performance obligations); and equity-based compensation (including the valuation of certain equity-based compensation awards issued by the Company). The Company bases its estimates on historical experience and on various other assumptions that are believed to be reasonable, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results may differ from these estimates. Foreign Currency The local currency is the functional currency for significant operations outside of the United States. The determination of the functional currency of an operation is made based upon the appropriate economic and management indicators. Foreign currency assets and liabilities are translated into their United States dollar equivalents based upon year end exchange rates, and are included in stockholders’ equity as a component of other comprehensive income (loss). Revenues and expenses are translated at average exchange rates. Transaction gains and losses that arise from exchange rate fluctuations are charged to operations as incurred, except for gains and losses associated with certain long-term intercompany transactions between subsidiaries for which settlement is not planned or anticipated in the foreseeable future, which are included in other comprehensive income (loss) in the accompanying statement of consolidated operations and comprehensive loss. The Company transacts business globally and is subject to risks associated with fluctuating foreign exchange rates. For 2020 and 2019, 54.8% and 60.8% of the consolidated revenue of the Company was derived from transactions outside the United States, respectively. This revenue is generated primarily from wholly-owned subsidiaries operating in their respective countries and surrounding geographic areas. This revenue is primarily denominated in each subsidiary’s local functional currency, including the euro and Japanese yen. Cash, Cash Equivalents, and Restricted Cash The Company considers all highly liquid instruments with maturities when purchased of three months or less to be cash equivalents. The Company’s policy is to invest cash in excess of short-term operating and debt-service requirements in such cash equivalents. These instruments are stated at cost, which approximates fair value because of the short maturity of the instruments. The Company maintains cash balances with financial institutions located in the United States, Germany and Japan. The Company places its cash with high quality financial institutions and believes its risk of loss is limited; however, at times, account balances may exceed international and federally insured limits. The Company has not experienced any losses associated with these cash balances. Restricted cash includes any cash balance held by the Company subject to restriction on withdrawal or use. Inventories The Company values all of its inventories at the lower of cost, as determined on the first-in, first-out method or net realizable value. Overhead is allocated to work in process and finished goods based upon normal capacity of the Company’s production facilities. Fixed overhead associated with production facilities that are being operated below normal capacity are recognized as a period expense rather than being capitalized as a product cost. An allowance for slow-moving and obsolete inventories is provided based on historical consumption experience, anticipated product demand and product design changes. These provisions reduce the cost basis of the respective inventories and are recorded as a charge to cost of sales. Property and Equipment Property and equipment are recorded at cost and depreciated on a straight-line basis over the estimated useful lives of the related assets, generally three to forty years. Leasehold improvements are amortized on a straight-line basis over the shorter of the estimated useful life of the asset or the expected term of the related lease. Gains or losses from the sale of assets are recognized upon disposal or retirement of the related assets. Repairs and maintenance are charged to expense as incurred. The Company evaluates long-lived assets held and used for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets (asset group) may not be recoverable. Recoverability of assets is determined by comparing the estimated undiscounted net cash flows of the operations related to the assets (asset group) to their carrying amount. An impairment loss would be recognized when the carrying amount of the assets (asset group) exceeds the estimated undiscounted net cash flows. The amount of the impairment loss to be recorded is calculated as the excess of carrying value of assets (asset group) over their fair value. The determination of what constitutes an asset group, the associated undiscounted net cash flows, the fair value of assets (asset group) and the estimated useful lives of assets require significant judgments and estimates by management. No impairment loss related to held and used assets was recorded by the Company during 2020 or 2019. Income Taxes The provision (benefit) for income taxes is determined using the asset and liability approach of accounting for income taxes. Under this approach, the provision (benefit) for income taxes represents income taxes paid or payable (or received or receivable) for the current year plus the change in deferred taxes during the year. Deferred taxes represent the future tax consequences expected to occur when the reported amounts of assets and liabilities are recovered or paid and result from differences between the financial and tax bases of assets and liabilities and are adjusted for changes in tax rates and tax laws when enacted. Valuation allowances are established when necessary to reduce deferred tax assets to the amount expected to be realized. The Company’s foreign subsidiaries are taxed as corporations under the taxing regulations of those respective countries. As a result, the accompanying statement of consolidated operations and comprehensive loss includes a provision (benefit) for income taxes related to these foreign jurisdictions. Any undistributed earnings are intended to be permanently reinvested in the respective subsidiaries, with the exception of ExOne Property GmbH. The deferred taxes on the outside basis difference of the Company’s investment in ExOne Property GmbH were not significant at December 31, 2020. The Company recognizes the income tax benefit from an uncertain tax position only if it is more likely than not that the income tax position will be sustained on examination by the taxing authorities based upon the technical merits of the position. The income tax benefits recognized in the consolidated financial statements from such positions are then measured based upon the largest amount that has a greater than 50% likelihood of being realized upon settlement. Income tax benefits that do not meet the more likely than not criteria are recognized when effectively settled, which generally means that the statute of limitations has expired or that the appropriate taxing authority has completed its examination even though the statute of limitations remains open. Interest and penalties related to uncertain tax positions are recognized as part of the provision (benefit) for income taxes and are accrued beginning in the period that such interest and penalties would be applicable under relevant tax law until such time that the related income tax benefits are recognized. Taxes on Revenue Producing Transactions Taxes assessed by governmental authorities on revenue producing transactions, including sales, excise, value added and use taxes, are recorded on a net basis (excluded from revenue) in the accompanying statement of consolidated operations and comprehensive loss. Research and Development The Company is involved in research and development of new methods and technologies relating to its products. Research and development expenses are charged to operations as they are incurred. The Company capitalizes the cost of certain materials, equipment and facilities that have alternative future uses in research and development projects or otherwise. Advertising Advertising costs are charged to expense as incurred and were not significant for 2020 or 2019. Defined Contribution Plan The Company sponsors a defined contribution savings plan under section 401(k) of the Internal Revenue Code. Under the plan, participating employees in the United States may elect to defer a portion of their pre-tax earnings, up to the Internal Revenue Service’s annual contribution limit. During 2020 and 2019, the Company made discretionary matching contributions of 50% of the first 8% of employee contributions, subject to certain Internal Revenue Service limitations. Discretionary matching contributions made by the Company during 2020 and 2019 were $307 and $304, respectively. Equity-Based Compensation The Company recognizes compensation expense for equity-based grants using the straight-line attribution method in which the expense is recognized ratably over the requisite service period based on the grant date fair value of the related award. Forfeitures of pre-vesting equity-based grants are recognized as they are incurred and result in an offset to equity-based compensation expense in the period of recognition. Fair value of equity-based awards is estimated on the date of grant using the Black-Scholes option pricing model. Fair Value of Financial Instruments Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The Company measures the fair value of financial assets and liabilities according to a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value and requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs. The three levels of the fair value hierarchy are as follows: Level 1 inputs are quoted prices in active markets for identical assets or liabilities that are accessible at the measurement date; Level 2 inputs include inputs other than Level 1 that are observable, either directly or indirectly, and Level 3 inputs are unobservable inputs in which little or no market data exists, therefore typically reflect management’s estimates of assumptions that market participants would use in pricing the asset or liability. The hierarchy gives the highest priority to quoted prices in active markets for identical assets or liabilities (Level 1) and the lowest priority to measurements involving significant unobservable inputs (Level 3). At December 31, 2020 and December 31, 2019, the Company had no financial instruments (assets or liabilities) measured at fair value on a recurring basis. COVID-19 In March 2020, the World Health Organization declared the novel strain of coronavirus a global pandemic (“COVID-19”) and recommended containment and mitigation measures worldwide. The impact of COVID-19 and the related economic, business and market disruptions were wide-ranging and continue to be significant. As a result of COVID-19, the Company was required to temporarily close its operations at its North Huntingdon, Pennsylvania facility for the period from March 23 through March 30, 2020. In response to COVID-19, the Company has incurred incremental costs associated with protecting the health and safety of the Company’s global workforce, enhanced sanitization of the Company’s global operating facilities, and information technology capabilities for employees operating remotely. Beginning in March 2020, restrictions imposed by various governmental authorities on both domestic and international shipping and travel have caused a disruption to the timing of delivery and installation of the Company’s 3D printing machines, resulting in negative impacts to the Company’s financial position, results of operations and cash flows. The duration and severity of the outbreak and its long-term impact on the Company’s business are uncertain at this time. The Company is unable to predict the impact that COVID-19 will have on its future financial position, results of operations and cash flows. Recently Issued Accounting Guidance The Company considers the applicability and impact of all Accounting Standards Updates (“ASUs”) issued by the Financial Accounting Standards Board (the “FASB”). Recently issued ASUs not listed below either were assessed and determined to be not applicable or are currently expected to have no impact on the consolidated financial statements of the Company. In June 2016, the FASB issued ASU 2016-13, “Financial Instruments – Credit Losses.” This ASU added a new impairment model (known as the current expected credit loss (“CECL”) model) that is based on expected losses rather than incurred losses. Under the new guidance, an entity recognizes as an allowance its estimate of expected credit losses. The CECL model applies to most debt instruments, trade receivables, lease receivables, financial guarantee contracts, and other loan commitments. The CECL model does not have a minimum threshold for recognition of impairment losses and entities will need to measure expected credit losses on assets that have a low risk of loss. As an SRC pursuant to Rule 12b-2 of the Exchange Act, these changes become effective for the Company on January 1, 2023. Management is currently evaluating the potential impact of these changes on the consolidated financial statements of the Company.

Common Stock Offerings

Common Stock Offerings	12 Months Ended
	Dec. 31, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Common Stock Offering	Note 2. Common Stock Offerings In June 2020, the Company entered into an equity distribution agreement (the “Oppenheimer Equity Distribution Agreement”) with Oppenheimer & Company, Inc. (“Oppenheimer”) pursuant to which Oppenheimer agreed to act as sales agent in the sale of up to $25,000 in the aggregate of ExOne common stock in “at-the-market offerings” as defined in Rule 415 under the Securities Act of 1933, as amended (the “Securities Act”). Sales of common stock under the Oppenheimer Equity Distribution Agreement ended in September 2020 when the offering limit ($25,000) was reached. Following completion of this offering, in September 2020, the Company entered into a separate equity distribution agreement (the “Canaccord Equity Distribution Agreement”) with Canaccord Genuity LLC (“Canaccord”), pursuant to which Canaccord agreed to act as sales agent in the sale of up to $25,000 in the aggregate of ExOne common stock in “at-the-market offerings” as defined in Rule 415 under the Securities Act. The terms of both the Oppenheimer Equity Distribution Agreement and the Canaccord Equity Distribution Agreement required a 3.0% commission on the sale of ExOne common stock as well as reimbursement of certain expenses incurred by the sales agent. During 2020, the Company sold 3,445,385 shares of common stock in the above-described at-the-market offerings (2,204,875 shares under the Oppenheimer Equity Distribution Agreement and 1,240,510 shares under the Canaccord Equity Distribution Agreement) at an average selling price of $11.82 per share, resulting in net proceeds to the Company (after deducting commissions) of $39,509. During 2020, the Company incurred expenses (other than commissions) associated with at-the-market offerings of $340. At December 31, 2020, $171 of the expenses (other than commissions) associated with the at-the-market offerings remained unpaid (included in accounts payable in the accompanying consolidated balance sheet). There have been no sales of shares of common stock in at-the-market offerings subsequent to December 31, 2020. In February 2021, the Company terminated the Canaccord Equity Distribution Agreement. Refer to Note 20 for further discussion related to the termination of the Canaccord Equity Distribution Agreement.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Accumulated Other Comprehensive Loss	Note 3. Accumulated Other Comprehensive Loss The following table summarizes changes in the components of accumulated other comprehensive income (loss) for the periods indicated: For the years ended December 31, 2020 2019 Foreign currency translation adjustments Balance at beginning of period $ (11,483 ) $ (10,748 ) Other comprehensive income (loss) 1,345 (735 ) Balance at end of period $ (10,138 ) $ (11,483 ) Foreign currency translation adjustments consist of the effect of translation of functional currency financial statements (denominated in the euro and Japanese yen) to the reporting currency of the Company (United States dollar) and certain long-term intercompany transactions between subsidiaries for which settlement is not planned or anticipated in the foreseeable future. There were no tax impacts related to income tax rate changes and no amounts were reclassified to earnings for any of the periods presented.

Loss Per Share

Loss Per Share	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Loss Per Share	Note 4. Loss Per Share The Company presents basic and diluted loss per common share amounts. Basic loss per common share is calculated by dividing net loss available to common stockholders by the weighted average number of common shares outstanding during the applicable period. Diluted loss per common share is calculated by dividing net loss available to common stockholders by the weighted average number of common shares and common equivalent shares outstanding during the applicable period. As the Company incurred a net loss during 2020 and 2019, basic average common shares outstanding and diluted average common shares outstanding were the same because the effect of potential shares of common stock, including stock options (641,232 — 2020 and 854,259 — 2019) and unvested restricted stock issued (188,891 — 2020 and 66,513 — 2019), was anti-dilutive. The information used to compute basic and diluted net loss per common share was as follows for the periods indicated: For the years ended December 31, 2020 2019 Net loss $ (14,924 ) $ (15,095 ) Weighted average shares outstanding (basic and diluted) 17,423,229 16,309,259 Net loss per common share: Basic $ (0.86 ) $ (0.93 ) Diluted $ (0.86 ) $ (0.93 )

Revenue

Revenue	12 Months Ended
	Dec. 31, 2020
Revenue From Contract With Customer [Abstract]
Revenue	Note 5. Revenue The Company derives revenue from the sale of 3D printing machines and 3D printed and other products, materials and services. Revenue is recognized when the Company satisfies its performance obligation(s) under a contract (either implicit or explicit) by transferring the promised product or service to a customer, which is when (or as) the customer obtains control of the product or service. A performance obligation is a promise in a contract to transfer a distinct product or service to a customer. A contract’s transaction price is allocated to each distinct performance obligation. Revenue is measured as the amount of consideration the Company expects to receive in exchange for transferring products or providing services. As such, revenue is recorded net of returns, allowances, customer discounts, and incentives. Sales, value add, and other taxes collected from customers and remitted to governmental authorities are accounted for on a net (excluded from revenue) basis. Shipping and handling costs are included in cost of sales. Certain of the Company’s contracts with customers contain multiple performance obligations. Sales of 3D printing machines may also include optional equipment, materials, replacement components and services (installation, training and other services, including maintenance services and/or an extended warranty). Certain other contracts have a single performance obligation, as the promise to transfer products or services is not separately identifiable from other promises in the contract and, therefore, not distinct. For contracts with multiple performance obligations, the Company allocates the contract’s transaction price to each performance obligation using the Company’s best estimate of stand-alone selling price for each distinct product or service in the contract, which is generally based on an observable price. The Company’s revenue from products is transferred to customers at a point in time. The Company’s contracts for 3D printing machines generally include substantive customer acceptance provisions. Revenue under these contracts is recognized when customer acceptance provisions have been satisfied. For all other product sales, the Company recognizes revenue at the point in time in which the customer obtains control of the product, which is generally when product title passes to the customer upon delivery. In certain cases, title does not transfer and revenue is not recognized until the customer has received the products at its physical location. The Company’s revenue from service arrangements includes deferred maintenance contracts and extended warranties that can be purchased at the customer’s option. The Company generally provides a standard one-year warranty on the Company’s 3D printing machines, which is considered an assurance type warranty, and not considered a separate performance obligation (Note 10). Revenue associated with deferred maintenance contracts is generally recognized at a point in time when the related services are performed where sufficient historical evidence indicates that the costs of performing the related services under the contract are not incurred on a straight-line basis, with such revenue recognized in proportion to the costs expected to be incurred. Revenue associated with extended warranties is generally recognized over time on a straight-line basis over the related contract period. The Company generates certain service revenues through the sale of research and development services. Revenue under research and development service contracts is generally recognized over time where progress is measured in a manner that reflects the transfer of control of the promised goods or services to the customer. Depending on the facts and circumstances surrounding each research and development service contract, revenue is recognized over time using either an input measure (based on the entity’s direct costs incurred in an effort to satisfy the performance obligations) or an output measure (specifically units or parts delivered, based upon certain customer acceptance and delivery requirements). A portion of the Company’s service revenue is generated through contracts with the federal government under fixed-fee, cost reimbursable and time and materials arrangements (certain of which may have periods of performance greater than one year). Revenue under these contracts is generally recognized over time using an input measure based upon direct costs incurred. The following table summarizes the Company’s revenue by product group for the periods indicated: For the years ended December 31, 2020 2019 3D printing machines $ 31,470 $ 27,232 3D printed and other products, materials and services 27,783 26,044 $ 59,253 $ 53,276 Revenue from 3D printing machines includes leasing revenue whereby the Company is the lessor of 3D printing machines to its customers. Leasing revenue is accounted for under FASB Accounting Standards Codification Topic 842 “Leases” (Note 11). The timing of revenue recognition, billings and cash collections results in billed receivables, unbilled receivables (contract assets) and deferred revenue and customer prepayments (contract liabilities) in the accompanying consolidated balance sheet. The Company considers a number of factors in its evaluation of the creditworthiness of its customers, including past due amounts, past payment history, and current economic conditions. For 3D printing machines, the Company’s terms of sale vary by transaction. To reduce credit risk in connection with 3D printing machine sales, the Company may, depending upon the circumstances, require customers to furnish letters of credit or bank guarantees or to provide advanced payment (either partial or in full). For 3D printed and other products and materials, the Company’s terms of sale generally require payment within 30 to 60 days During 2020, the Company recognized revenue of $9,343 related to contract liabilities at January 1, 2020. The difference between revenue recognized related to contract liabilities at January 1, 2020 and the current portion of contract liabilities at December 31, 2019 is principally due to customer prepayments of $2,241 received prior to January 1, 2020 for two 3D printing machine sales the Company expected to complete during 2020. These 3D printing machine sales are now expected to be completed during 2021. Contract assets were not significant during the year ended December 31, 2020. At December 31, 2020, the Company had approximately $39,400 of remaining performance obligations (including contract liabilities), which is also referred to as backlog, of which approximately $33,000 is expected to be fulfilled during the next 12 months notwithstanding uncertainty related to the impact of COVID-19 (Note 1), including, but not limited to, international shipping and travel restrictions brought about by COVID-19, which could have an adverse effect on the timing of delivery and installation of products and/or services to customers. The Company has elected to apply the practical expedient associated with incremental costs of obtaining a contract, and as such, sales commission expense is generally expensed when incurred because the amortization period would be one year or less. These costs are recorded within selling, general and administrative expenses. Accounts receivable and net investment in sales-type leases (Note 11) are reported at their net realizable value. The Company carries its investment in sales-type leases based on discounting the minimum lease payments by the interest rate implicit in the lease, less an allowance for doubtful accounts. The Company’s estimate of the allowance for doubtful accounts related to accounts receivable and net investment in sales-type leases is based on the Company’s evaluation of customer accounts with past-due outstanding balances or specific accounts for which it has information that the customer may be unable to meet its financial obligations. Based upon review of these accounts, and management’s analysis and judgment, the Company records a specific allowance for that customer’s accounts receivable or net investment in sales-type lease balance to reduce the outstanding balance to the amount expected to be collected. The allowance is re-evaluated and adjusted periodically as additional information is received that impacts the allowance amount reserved. At December 31, 2020 and 2019, the allowance for doubtful accounts was $576

Cash, Cash Equivalents, and Res

Cash, Cash Equivalents, and Restricted Cash	12 Months Ended
	Dec. 31, 2020
Cash And Cash Equivalents [Abstract]
Cash, Cash Equivalents, and Restricted Cash	Note 6. Cash, Cash Equivalents, and Restricted Cash The following provides a reconciliation of cash, cash equivalents, and restricted cash as reported in the accompanying consolidated balance sheet to the same such amounts shown in the accompanying statement of consolidated cash flows at December 31: 2020 2019 Cash and cash equivalents $ 49,668 $ 5,265 Restricted cash 508 978 Cash, cash equivalents, and restricted cash $ 50,176 $ 6,243 Restricted cash at both December 31, 2020 and December 31, 2019 included $508 of cash collateral required by a United States bank to offset certain short-term, unsecured lending commitments associated with the Company’s corporate credit card program. Restricted cash at December 31, 2019 also included $470 of cash collateral required by a German bank for short-term financial guarantees issued by ExOne GmbH in connection with certain commercial transactions requiring security. Refer to Note 12 for further discussion related to an amendment to this cash collateral requirement effective in February 2020. Each of the balances discussed above are considered legally restricted by the Company.

Inventories

Inventories	12 Months Ended
	Dec. 31, 2020
Inventory Disclosure [Abstract]
Inventories	Note 7. Inventories Inventories consisted of the following at December 31: 2020 2019 Raw materials and components $ 9,436 $ 8,841 Work in process 4,797 4,922 Finished goods 6,329 6,007 $ 20,562 $ 19,770 Raw materials and components consist of consumable materials and component parts and subassemblies associated with 3D printing machine manufacturing and support activities. Work in process consists of 3D printing machines and other products in varying stages of completion. Finished goods consist of 3D printing machines and other products prepared for sale in accordance with customer specifications. At December 31, 2020 and 2019 , the allowance for slow-moving and obsolete inventories was $2,678 and $3,443 , respectively , and has been reflected as a reduction to inventories (principally raw mate rials and components). The following table summarizes changes in the allowance for slow-moving and obsolete inventories for the periods indicated: 2020 2019 Balance at beginning of period $ 3,443 $ 4,143 Provision for slow-moving and obsolete inventories ̶ net 218 292 Reductions for physical disposal (sale or scrap) of previously reserved amounts (1,181 ) (914 ) Foreign currency translation adjustments 198 (78 ) Balance at end of period $ 2,678 $ 3,443 Reductions for sale, consumption or scrap of previously reserved amounts during 2020 consisted principally of certain raw material and component inventories associated with the Company’s former Exerial 3D printing platform, which were disposed of during the period. There was no significant benefit or charge recorded during the period in connection with the related disposals. During 2020, the Company recorded a charge of $205 to cost of sales in the accompanying statement of consolidated operations and comprehensive loss associated with certain inventories for which cost was determined to exceed net realizable value.

Property and Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2020
Long Lived Assets [Abstract]
Property and Equipment	Note 8. Property and Equipment Property and equipment consisted of the following at December 31: 2020 2019 Economic Life (in years) Land $ 3,494 $ 6,980 N/A Buildings and related improvements 10,246 25,675 5 - 40 Machinery and equipment 20,728 19,531 3 - 20 Other 6,291 7,086 3 - 20 40,759 59,272 Less: Accumulated depreciation (20,823 ) (21,478 ) 19,936 37,794 Construction-in-progress 1,364 1,101 Property and equipment ̶ net $ 21,300 $ 38,895 Machinery and equipment included assets leased by the Company of $142 and $63 at December 31, 2020 and 2019, respectively. Machinery and equipment included assets leased to customers (principally 3D printing machines and related equipment) under operating lease arrangements of $1,920 and $1,309 at December 31, 2020 and 2019, respectively. The carrying value of these assets was Depreciation expense was $3,775 and $4,581 for 2020 and 2019, respectively. On February 18, 2020, the Company completed a sale-leaseback transaction associated with its European headquarters and operating facility in Gersthofen, Germany (Note 11). As a result of the completion of this transaction, the Company derecognized $17,282 in net property and equipment during 2020. In connection with the sale of the facility, the Company recorded a gain of $1,462 during 2020.

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	12 Months Ended
	Dec. 31, 2020
Payables And Accruals [Abstract]
Accrued Expenses and Other Current Liabilities	Note 9. Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consisted of the following at December 31: 2020 2019 Accrued license fees $ 1,563 $ 1,020 Product warranty reserves 1,335 866 Accrued payroll and related costs 1,089 1,382 Accrued professional fees 252 272 Income taxes payable 1 503 Deposit liability on sale of property and equipment — 2,243 Other 738 656 $ 4,978 $ 6,942

Product Warranty Reserves

Product Warranty Reserves	12 Months Ended
	Dec. 31, 2019
Product Warranties Disclosures [Abstract]
Product Warranty Reserves	Note 10. Product Warranty Reserves Substantially all of the Company’s 3D printing machines are covered by a standard one-year warranty. Generally, at the time of sale, a liability is recorded (with an offset to cost of sales) based upon the expected cost of replacement parts and labor to be incurred over the life of the standard warranty. Expected cost is estimated using historical experience for similar products. The Company periodically assesses the adequacy of the product warranty reserves based on changes in these factors and records any necessary adjustments if actual experience indicates that adjustments are necessary. Future claims experience could be materially different from prior results because of the introduction of new, more complex products, a change in the Company’s warranty policy in response to industry trends, competition or other external forces, or manufacturing changes that could impact product quality. In the event that the Company determines that its current or future product repair and replacement costs exceed estimates, an adjustment to these reserves would be charged to cost of sales in the period such a determination is made. The following table summarizes changes in product warranty reserves, which amounts were reflected in accrued expenses and other current liabilities in the accompanying consolidated balance sheet for the periods indicated: For the year ended December 31, 2020 2019 Balance at beginning of period $ 866 $ 1,670 Provisions for new issuances 1,318 1,125 Payments (1,920 ) (1,514 ) Reserve adjustments 1,033 (399 ) Foreign currency translation adjustments 38 (16 ) Balance at end of period $ 1,335 $ 866

Leases

Leases	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Leases	Note 11. Leases Lessee The Company leases facilities, machinery and other equipment and vehicles under operating lease arrangements (with initial terms greater than 12 months), expiring in various years through 2026. In addition, the Company leases certain equipment and vehicles under finance lease arrangements, which are not significant. For all operating lease arrangements (with the exception of short-term lease arrangements), the Company presents at the commencement date: a lease liability, which is a lessee’s obligation to make lease payments arising from a lease, measured on a discounted basis; and a right-of-use asset, which is an asset that represents the lessee’s right to use, or control the use of, a specified asset for the lease term. The Company has elected, as a practical expedient, not to separate non-lease components from lease components, and instead accounts for each separate component as a single lease component for all lease arrangements, as lessee. In addition, the Company has elected, as a practical expedient, not to apply lease recognition requirements to short-term lease arrangements, generally those with a lease term of less than 12 months, for all classes of underlying assets. In determination of the lease term, the Company considers the likelihood of lease renewal options and lease termination provisions. As a result, lease payments under these short-term lease arrangements are recognized in the accompanying statement of consolidated operations and comprehensive loss on a straight-line basis over the lease term. The Company uses its incremental borrowing rate in determining the present value of lease payments, as the implicit rate of the lease arrangements is generally not readily determinable. Future minimum lease payments of operating lease arrangements (with initial terms greater than 12 months) at December 31, 2020, were as follows: 2021 $ 2,119 2022 2,082 2023 48 2024 13 2025 2 Thereafter 1 Total minimum lease payments 4,265 Less: Present value discount (222 ) Total operating lease liabilities $ 4,043 For 2020 and 2019, lease cost under operating lease arrangements was $2,115 (including $126 relating to short-term lease arrangements) and $389 (including $189 related to short-term lease arrangements), respectively. Supplemental information related to operating lease arrangements (with initial terms greater than 12 months) was as follows as of and for the year then ended December 31: 2020 2019 Right-of-use assets obtained in exchange for new operating lease liabilities $ 4,909 $ 209 Cash paid for amounts included in the measurement of operating lease liabilities $ 2,009 $ 198 Weighted average remaining lease term (in years) 2.1 3.1 Weighted average discount rate 5.1 % 5.5 % On December 10, 2019, ExOne Property GmbH and ExOne GmbH, the German subsidiaries of the Company (the “German Subsidiaries”), entered into a purchase agreement (the “Purchase Agreement”) with Solidas Immobilien und Grundbesitz GmbH, a private, unaffiliated German real estate investor (the “Buyer”), for the sale of the Company’s European headquarters and operating facility in Gersthofen, Germany (the “Facility”) for a purchase price of approximately $18,500 (€17,000), of which approximately $2,200 (€2,000) was received prior to December 31, 2019. Concurrent with the execution of the Purchase Agreement, ExOne GmbH and the Buyer entered into a rental contract (the “Lease”) for the leaseback of the Facility for an initial aggregate annual rent totaling approximately $1,700 (€1,500), plus applicable taxes, which is fixed during the initial three-year five-year Lessor The Company leases machinery and equipment to customers (principally 3D printing machines and related equipment) under lease arrangements classified as either operating leases or sales-type leases. The Company’s operating lease arrangements have initial terms generally ranging from one to five years, certain of which may contain extension or termination clauses, or both. Such operating lease arrangements also generally include a purchase option to acquire the related machinery and equipment at the end of the lease term for either a fixed amount as determined at inception, or a subsequently negotiated fair market value. At December 31, 2020, the Company estimated that the total fair market value significantly exceeded the related net book value of the machinery and equipment held under the Company’s operating lease arrangements. The Company’s sales-type lease arrangements generally include transfer of ownership at the end of the lease term, and as such, the Company’s net investment in sale-type lease arrangements presented in the Company’s accompanying consolidated balance sheet generally does not include an amount of unguaranteed residual value. For certain of its arrangements, the Company separates and allocates (Note 5) certain non-lease components (principally maintenance services) from lease components. Sales, value add, and other taxes collected from customers and remitted to governmental authorities are accounted for on a net (excluded from lease income) basis. In determination of the lease term, the Company considers the likelihood of lease renewal options and lease termination provisions. The Company recognized the following components under operating and sales-type lease arrangements in the accompanying statement of consolidated operations and comprehensive loss for the periods indicated: For the years ended December 31, 2020 2019 Operating Sales-type Operating Sales-type Revenue $ 785 $ — $ 1,523 $ — Interest income (a) $ — $ 62 $ — $ 94 (a) Interest income related to sales-type leases is recorded as a component of revenue in the accompanying statement of consolidated operations and comprehensive loss for each of the periods presented . The Company’s net investment in sales-type leases consisted of the following at December 31: 2020 2019 Future minimum lease payments receivable $ 1,368 $ 1,595 Less: Allowance for doubtful accounts (463 ) (501 ) Net future minimum lease payments receivable 905 1,094 Less: Unearned interest income (167 ) (143 ) Net investment in sales-type leases $ 738 $ 951 During 2019, the Company recorded a provision for bad debt of $416 based on a deterioration in credit quality of a lessee. There were no such provisions recorded during 2020. Future minimum lease payments of non-cancellable operating and sales-type lease arrangements as of December 31, 2020, were as follows: Operating Sales-type 2021 $ 414 $ 554 2022 — 390 2023 — 424 2024 — — 2025 — — Thereafter — — Total minimum lease payments $ 414 $ 1,368 Less: Allowance for doubtful accounts (463 ) Less: Present value discount (167 ) Future minimum lease payments receivable $ 738

Contingencies and Commitments

Contingencies and Commitments	12 Months Ended
	Dec. 31, 2020
Commitments And Contingencies Disclosure [Abstract]
Contingencies and Commitments	Note 12. Contingencies and Commitments Contingencies On March 1, 2018, the Company’s ExOne GmbH subsidiary notified Voxeljet AG that it had materially breached a 2003 Patent and Know-How Transfer Agreement and asserted its rights to set-off damages as a result of the breaches against the annual license fee due from the Company under the agreement. At this time, the Company cannot reasonably estimate a contingency, if any, related to this matter. The Company is subject to various litigation, claims, and proceedings which have been or may be instituted or asserted from time to time in the ordinary course of business. Management does not believe that the outcome of any pending or threatened matters will have a material adverse effect, individually or in the aggregate, on the financial position, results of operations or cash flows of the Company . Commitments In the normal course of its operations, ExOne GmbH issues short-term financial guarantees and letters of credit to third parties in connection with certain commercial transactions requiring security through a credit facility with a German bank. On February 24, 2020, ExOne GmbH entered into an amendment and replacement of its credit facility with the German bank. The credit facility amendments included the elimination of the overdraft credit and short-term loan features of the prior agreement and replaced them with an increased capacity amount of approximately $4,300 (€3,500) for the issuance of financial guarantees and letters of credit for commercial transactions requiring security. The cash collateral requirement for the issuance of financial guarantees and letters of credit for commercial transactions requiring security was eliminated for amounts up to approximately $1,200 (€1,000) as the amendment provided the German bank with a collateral interest in the accounts receivable of ExOne GmbH. Amounts in excess of approximately $1,200 (€1,000) continue to require cash collateral under the amended credit facility. At December 31, 2020, total outstanding financial guarantees and letters of credit issued by ExOne GmbH under the amended credit facility were $928 (€756), with expiration dates ranging from March 2021 December 2021

Related Party Revolving Credit

Related Party Revolving Credit Facility	12 Months Ended
	Dec. 31, 2020
Related Party Transactions [Abstract]
Related Party Revolving Credit Facility	Note 13. Related Party Revolving Credit Facility On March 12, 2018, the Company and its ExOne Americas LLC and ExOne GmbH subsidiaries, as guarantors (collectively, the “Loan Parties”), entered into a Credit Agreement and related ancillary agreements with LBM Holdings, LLC (“LBM”), a company controlled by S. Kent Rockwell, who was the Executive Chairman of the Company (a related party) at such date and is currently Chairman of the Company, relating to a $15,000 revolving credit facility (the “Credit Agreement”) to provide additional funding to the Company for working capital and general corporate purposes. The Credit Agreement provided a credit facility for a term of three years (through March 12, 2021), bearing interest at a rate of one-month LIBOR plus an applicable margin of 500 basis points (5.1% at December 31, 2020 and 6.8% at December 31, 2019). The Credit Agreement required a commitment fee of 75 basis points, or 0.75%, on the unused portion of the facility, payable monthly in arrears. In addition, an up-front commitment fee of 125 basis points, or 1.25% ($188), was required at closing. Borrowings under the Credit Agreement were collateralized by the accounts receivable, inventories and machinery and equipment of the Loan Parties. On February 18, 2020, the Loan Parties and LBM entered into a First Amendment to the Credit Agreement (the “Amendment”) which (i) reduced the available capacity under the revolving credit facility to $10,000, (ii) extended the term of the credit facility until March 31, 2024, (iii) increased the commitment fee to 100 basis points, or 1.00%, on the unused portion of the revolving credit facility, and (iv) provided a process for the replacement of the LIBOR index after 2021. In addition, the accounts receivable of ExOne GmbH no longer served as collateral for borrowings under the amended revolving credit facility. Borrowings under the credit facility were required to be made in minimum increments of $1,000. The Company could make prepayments against outstanding borrowings under the amended Credit Agreement at any time without penalty. At December 31, 2020 and 2019, the total estimated value of collateral was in significant excess of the maximum borrowing capacity under the credit facility. The amended Credit Agreement contained several affirmative covenants including prompt payment of liabilities and taxes; maintenance of insurance, properties, and licenses; and compliance with laws. The amended Credit Agreement also contained several negative covenants including restricting the incurrence of certain additional debt; prohibiting future liens (other than permitted liens); prohibiting investment in third parties; limiting the ability to pay dividends; limiting mergers, acquisitions, and dispositions; and limiting the sale of certain property and equipment of the Loan Parties. The amended Credit Agreement did not contain any financial covenants. The amended Credit Agreement also contained events of default, including, but not limited to, cross-default to certain other debt, breaches of representations and warranties, change of control events and breaches of covenants. The Company obtained waivers related to its event of default on its building note payable (Note 14) and for the incurrence of additional debt associated with its PPP Loan (Note 14). The Company did not consider the Credit Agreement, as amended, indicative of a fair market value lending, as LBM was determined to be a related party based on common control by S. Kent Rockwell. S. Kent Rockwell is the indirect sole owner of LBM. Prior to execution, each of the Credit Agreement and the Amendment was reviewed and approved by the Audit Committee of the Company’s Board of Directors (the “Board”), in accordance with The ExOne Company Policy and Procedures with Respect to Related Person Transactions, and subsequently by a sub-committee of independent members of the Board. At the time of execution of the Credit Agreement, the available loan proceeds were deposited into an escrow account with an unrelated, third party financial institution acting as escrow agent pursuant to a separate escrow agreement by and among the parties. Loan proceeds held in escrow were available to the Company upon its submission to the escrow agent of a loan request. Such proceeds were not available to LBM until payment in-full of the obligations under the amended Credit Agreement and termination of the amended Credit Agreement. Payments of principal and other obligations were to be made to the escrow agent, while interest payments were to be made directly to LBM. Provided there existed no potential default or event of default, the amended Credit Agreement and the escrow agreement prohibited any acceleration of repayment of any amount outstanding under the amended Credit Agreement and prohibited termination of the amended Credit Agreement or withdrawal from escrow of any unused portion of the available loan proceeds. There were no borrowings under the credit facility during 2020. During 2019, the Company had borrowings of $4,000, all of which were subsequently repaid prior to December 31, 2019. The Company incurred $265 in debt issuance costs associated with the inception of the credit facility (including the aforementioned up-front commitment fee paid at closing to LBM) and $49 in debt issuance costs associated with the Amendment. During 2020, the Company recorded interest expense related to the credit facility of $147. Included in interest expense for 2020 was $44 associated with amortization of debt issuance costs (resulting in $111 in remaining debt issuance costs at December 31, 2020, of which $35 was included in prepaid expenses and other current assets and $76 was included in other noncurrent assets in the accompanying consolidated balance sheet). Included in interest expense for 2020 was $103 associated with the commitment fee on the unused portion of the revolving credit facility. During 2019, the Company recorded interest expense related to the credit facility of $260. At December 31 , 2020 and 2019, $ 9 and $ 28 , respectively, associated with the commitment fee on the unused portion of the revolving credit facility were included in accounts payable on the accompanying consolidated balance sheet. Amounts payable to LBM at December 31 , 2020 and 2019 were settled by the Company in January 2021 and January 2020, respectively. Under the terms of the amended Credit Agreement, the Company could terminate or reduce the credit commitment at any time during the term without penalty. In March 2021, the Company terminated the credit facility with LBM. Refer to Note 20 for further discussion related to the termination of the credit facility.

Long-Term Debt

Long-Term Debt	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Long-Term Debt	Note 14. Long-Term Debt Long-term debt consisted of the following at December 31: 2020 2019 Principal Unamortized Debt Issuance Costs Net Principal Unamortized Debt Issuance Costs Net Paycheck Protection Program loan $ 2,194 $ — $ 2,194 $ — $ — $ — Building note payable 1,226 (15 ) 1,211 1,384 (20 ) 1,364 Less: Amount due within one year (1,626 ) 4 (1,622 ) (157 ) 4 (153 ) $ 1,794 $ (11 ) $ 1,783 $ 1,227 $ (16 ) $ 1,211 On April 18, 2020, the Company entered into an unsecured promissory note (the “Note”) with a United States bank (the “Lender”) reflecting a loan in the principal amount of $2,194 (the “Loan”). The Loan was granted pursuant to the Paycheck Protection Program (the “PPP”) administered by the United States Small Business Administration (the “SBA”) as part of the Coronavirus Aid, Relief, and Economic Security Act (the “CARES Act”). Pursuant to the terms of the Note, the Loan bears interest at a rate of 1.00% per annum and matures on April 18, 2022 (the “Maturity Date”). Under the terms of the Note, principal and interest payments on the Loan were deferred until November 18, 2020, at which time equal installments of principal and interest would be due and payable monthly through the Maturity Date. Subsequent to the Company entering into the Note, in June 2020, the Paycheck Protection Program Flexibility Act of 2020 was enacted, which extended the deferral of principal and interest payments on the Loan from November 18, 2020 to May 18, 2021. The Note may be prepaid by the Company at any time prior to maturity without penalty. If the Company defaults on the Note, the Lender may, at its option, accelerate the maturity of the Company’s obligations under the Note. Pursuant to the terms of the PPP, the Loan, or a portion thereof, may be forgiven if Loan proceeds are used for qualifying expenses as described in the CARES Act, such as payroll costs, costs used to continue group health care benefits, mortgage interest payments, rent and utilities. The Company used all of the Loan proceeds for qualifying expenses. The terms of the Loan, including eligibility and forgiveness, may be subject to further requirements in the Paycheck Protection Program Flexibility Act of 2020 and in regulations and guidance adopted by the SBA. The Company has elected to account for the Loan in accordance with the terms of the Note while its forgiveness eligibility remains subject to review. On May 21, 2012, the Company entered into a building note payable with a United States bank. Terms of the building note payable include monthly payments of $18, including interest at 4.00% through May 2017, and subsequently, monthly payments of $19 including interest at the monthly average yield on United States Treasury Securities plus 3.25% for the remainder of the term through May 2027. The building note payable is collateralized by the Company’s facility located in North Huntingdon, Pennsylvania which had a carrying value of $4,795 at December 31, 2020. At December 31, 2020, the Company identified that it was not in compliance with the annual cash flow-to-debt service ratio covenant associated with the building note payable. The Company requested and was granted a waiver related to compliance with this annual covenant at December 31, 2020 and through December 31, 2021. Related to the 2020 non-compliance, there were no cross-default provisions or related impacts on other lending or financing agreements (Note 13). Future maturities of long-term debt at December 31, 2020, were as follows: 2021 $ 1,626 2022 912 2023 188 2023 195 2025 201 Thereafter 298 $ 3,420 At December 31, 2020 and 2019, the fair value of long-term debt was $3,382 and $1,384, respectively. The fair value of long-term debt has been estimated by management based on the consideration of applicable interest rates, including certain instruments at variable or floating rates and the nominal fixed interest rate (1.0%) associated with the Company’s PPP Loan and other available information (including quoted prices of similar instruments available to the Company). The fair value of long-term debt was measured using Level 2 inputs (Note 1). In February 2021, the Company extinguished the building note payable. Refer to Note 20 for further discussion related to the extinguishment of the building note payable.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	Note 15. Income Taxes The components of loss before taxes were as follows: 2020 2019 United States $ (17,584 ) $ (16,452 ) Foreign 2,860 950 Loss before income taxes $ (14,724 ) $ (15,502 ) The provision (benefit) for income taxes consisted of the following for year ended December 31: 2020 2019 Current Deferred Total Current Deferred Total United States $ 5 $ — $ 5 $ 4 $ — $ 4 Foreign — 195 195 (212 ) (199 ) (411 ) Provision (benefit) for income taxes $ 5 $ 195 $ 200 $ (208 ) $ (199 ) $ (407 ) A reconciliation of the provision (benefit) for income taxes at the United States statutory rate to the effective rate of the Company for the years ended December 31 was as follows: 2020 2019 United States statutory rate (21%) $ (3,092 ) $ (3,255 ) Effect of foreign disregarded entity 329 (151 ) Taxes on foreign operations 76 64 Net change in valuation allowances 3,824 4,224 Reduction in uncertain tax positions — (818 ) Permanent differences (728 ) 83 Return to provision adjustments 133 (163 ) Deferred tax adjustments (291 ) (318 ) Other (51 ) (73 ) Provision (benefit) for income taxes $ 200 $ (407 ) Effective tax rate (1.4 )% 2.6 % The components of deferred income tax assets and liabilities consisted of the following at December 31: 2020 2019 Deferred tax assets Accounts receivable $ 116 $ 110 Inventories 597 710 Accrued expenses and other current liabilities 1,352 477 Net operating loss carryforwards 32,582 27,710 Tax credit carryforwards 676 676 Other 961 1,968 Valuation allowance (34,881 ) (30,666 ) Total deferred tax assets 1,403 985 Deferred tax liabilities Property and equipment 539 690 Other 864 94 Total deferred tax liabilities 1,403 784 Net deferred tax assets (a) $ — $ 201 (a) At December 31, 2019, net deferred tax assets were reflected in other noncurrent assets in the accompanying consolidated balance sheet. The Company has provided a valuation allowance for certain of its net deferred tax assets as a result of the Company not generating consistent net operating profits in certain jurisdictions in which it operates. As such, certain benefits from deferred taxes in any of the periods presented have been fully offset by changes in the valuation allowance for net deferred tax assets. The Company continues to assess its future taxable income by jurisdiction based on recent historical operating results, the expected timing of reversal of temporary differences, various tax planning strategies that the Company may be able to enact in future periods, the impact of potential operating changes on the business and forecast results from operations in future periods based on available information at the end of each reporting period. To the extent that the Company is able to reach the conclusion that its net deferred tax assets are realizable based on any combination of the above factors in a single, or in multiple, taxing jurisdictions, a reversal of the related portion of the Company’s existing valuation allowances may occur. The following table summarizes changes to the Company’s valuation allowances for the years ended December 31: 2020 2019 Balance at beginning of period $ 30,666 $ 26,563 Net increases in allowances 3,824 3,857 Net increases in net operating losses offset by uncertain tax positions — 368 Foreign currency translation adjustments 391 (122 ) Balance at end of period $ 34,881 $ 30,666 At December 31, 2020, the Company had $115,285 in net operating loss carryforwards, subject to certain limitations, $70,761 of which expire from 2033 to 2037, and $676 in tax credit carryforwards which begin to expire in 2023, to offset the future taxable income of its United States subsidiary. At December 31, 2020, the Company had United States state net operating loss carryforwards of $11,567, subject to certain limitations, which begin to expire in 2023. At December 31, 2020, the Company had $2,549 in net operating loss carryforwards which expire from 2022 through 2026, to offset the future taxable income of its Japanese subsidiary. At December 31, 2020, the Company had $24,450 in net operating loss carryforwards, which do not expire but may be limited as to their use in a particular period, to offset the future taxable income of its German subsidiary. A reconciliation of the beginning and ending amount of unrecognized tax benefits (including accrued interest and penalties) at December 31 was as follows: 2020 2019 Balance at beginning of period $ — $ 1,186 Additions based on tax positions related to the current year — — Additions for tax positions of prior years — 5 Reductions for tax positions of prior years — (1,186 ) Settlements — — Foreign currency translation adjustments — (5 ) Balance at end of period $ — $ — The Company includes interest and penalties related to income taxes as a component of the provision (benefit) for income taxes in the accompanying statement of consolidated operations and comprehensive loss (there were no such interest or penalties included in the provision (benefit) for income taxes in 2020 or 2019). During 2019, the Company’s ExOne GmbH (2010-2014 tax years) and ExOne Property GmbH (2013-2014 tax years) subsidiaries were under examination by local taxing authorities in Germany. In January 2019, the examination of ExOne GmbH (2010-2013 tax years) and ExOne Property GmbH (2013 tax year) was concluded by the local taxing authorities in Germany without significant adjustment to previously established tax positions. As a result, during 2019, the Company recorded a reversal of certain of its previously recorded liabilities for uncertain tax positions of $1,075, of which $257 was offset against net operating loss carryforwards. In December 2019, the examination of ExOne GmbH (2014 tax year) and ExOne Property GmbH (2014 tax year) was concluded by the local taxing authorities in Germany without significant adjustment to previously established tax positions. As a result, during 2019, the Company recorded a reversal of certain of its previously recorded liabilities for uncertain tax positions of $111, all of which was offset against net operating loss carryforwards. The Company files income tax returns in the United States, Germany, and Japan. The Company filed income tax returns in Italy through 2018. The following table summarizes tax years remaining subject to examination for each of the Company’s subsidiaries at December 31, 2020: Jurisdiction Tax Years Remaining Subject to Examination United States 2017-2020 Germany 2016-2020 Japan 2018-2020 Italy 2015-2018

Equity-Based Compensation

Equity-Based Compensation	12 Months Ended
	Dec. 31, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Equity-Based Compensation	Note 16. Equity-Based Compensation On January 24, 2013, the Board adopted the 2013 Equity Incentive Plan (the “Plan”). In connection with the adoption of the Plan, 500,000 shares of common stock were reserved for issuance pursuant to the Plan, with automatic increases in such reserve available each year annually on January 1 from 2014 through 2023 equal to the lesser of 3.0% of the total outstanding shares of common stock as of December 31 of the immediately preceding year, or a number of shares of common stock determined by the Board, provided that the maximum number of shares authorized under the Plan could not exceed 1,992,241 shares, subject to certain adjustments. The maximum number of shares authorized under the Plan was reached on January 1, 2017. At December 31, 2020, 499,189 shares remained available for future issuance under the Plan Stock options and restricted stock issued by the Company under the Plan are generally subject to service conditions resulting in annual vesting on the anniversary of the date of grant over a period typically ranging between one and three years. Certain equity-based compensation awards issued by the Company under the Plan vest immediately upon issuance. Stock options issued by the Company under the Plan have contractual lives which expire over a period typically ranging between five and ten years from the date of grant, subject to continued service to the Company by the participant . On February 6, 2019, the Compensation Committee of the Board adopted the 2019 Annual Incentive Program (the “2019 Program”) as a subplan under the Plan. The 2019 Program provided an opportunity for performance-based compensation in the form of common stock to senior executive officers of the Company, among others. The target annual incentive for each 2019 Program participant was expressed as a percentage of base salary and was conditioned on the achievement of certain financial goals (as approved by the Compensation Committee of the Board). The Compensation Committee of the Board retained negative discretion over amounts payable under the 2019 Program. During 2019, there was no compensation expense associated with the 2019 Program as a result of underperformance against the 2019 financial goals of the Company. No shares of vested common stock were issued in connection with the 2019 Program. On February 5, 2020, the Compensation Committee of the Board adopted the 2020 Annual Incentive Program (the “2020 Program”) as a subplan under the Plan. The 2020 Program provided an opportunity for performance-based compensation in the form of common stock to senior executive officers of the Company, among others. The target annual incentive for each 2020 Program participant was expressed as a percentage of base salary and was conditioned on the achievement of certain financial goals (as approved by the Compensation Committee of the Board). The Compensation Committee of the Board retained negative discretion over amounts payable under the 2020 Program. During 2020, there was no compensation expense associated with the 2020 Program as a result of underperformance against the 2020 financial goals of the Company. No shares of vested common stock were issued in connection with the 2020 Program as a result. The following table summarizes the total equity-based compensation expense recognized by the Company : 2020 2019 Equity-based compensation expense recognized: Stock options $ 417 $ 709 Restricted stock 790 696 Other (a) 18 11 Total equity-based compensation expense before income taxes 1,225 1,416 Benefit for income taxes (b) — — Total equity-based compensation expense net of income taxes $ 1,225 $ 1,416 (a) For both periods presented, Other represents expense associated with certain employee contractual amounts to be settled in equity. (b) The benefit for income taxes from equity-based compensation for each of the periods presented has been determined to be $0 At December 31, 2020, total future compensation expense related to unvested awards yet to be recognized by the Company was $295 The fair value of stock options was estimated on the date of grant using the Black-Scholes option pricing model with the following assumptions: 2020 2019 Weighted average fair value per stock option $4.55 - $6.20 $2.51 - $3.68 Volatility 58.0% - 63.5% 53.3% - 60.1% Average risk-free interest rate 0.2% 1.5% - 2.5% Dividend yield 0.0% 0.0% Expected term (years) 2.5 - 3.5 2.5 - 3.5 Volatility is estimated based on the historical volatility of the Company’s stock price consistent with the expected term of the awards. The average risk-free rate is based on a weighted average yield curve of risk-free interest rates consistent with the expected term of the awards. Expected dividend yield is based on historical dividend data as well as future expectations. Expected term is calculated using the simplified method as the Company does not have sufficient historical exercise experience upon which to base an estimate. The activity for stock options was as follows for the year ended December 31: 2020 2019 Number Options Weighted Exercise Price Weighted Average Grant Date Fair Value Number Options Weighted Exercise Price Weighted Average Grant Date Fair Value Outstanding at beginning of period 854,259 $ 9.34 $ 4.49 621,986 $ 10.66 $ 5.52 Stock options granted 28,188 $ 14.12 $ 5.83 319,310 $ 7.34 $ 2.94 Stock options exercised (127,854 ) $ 7.30 $ 3.12 (40,432 ) $ 7.17 $ 3.03 Stock options forfeited (81,186 ) $ 7.83 $ 3.40 (9,773 ) $ 7.67 $ 3.70 Stock options expired (32,175 ) $ 12.94 $ 7.44 (36,832 ) $ 16.94 $ 10.35 Outstanding at end of period 641,232 $ 9.80 $ 4.74 854,259 $ 9.34 $ 4.49 Exercisable at end of period 502,260 $ 10.40 $ 5.21 494,884 $ 10.85 $ 5.59 Expected to vest at end of period 138,972 $ 7.65 $ 3.01 359,375 $ 7.27 $ 2.96 At December 31, 2020, intrinsic value associated with stock options exercisable and stock options expected to vest was $493 The activity for restricted stock was as follows for the year ended December 31: 2020 2019 Shares of Restricted Stock Weighted Average Grant Date Fair Value Shares of Restricted Stock Weighted Average Grant Date Fair Value Outstanding at beginning of period 66,513 $ 8.76 67,001 $ 8.30 Restricted stock granted 209,891 $ 9.58 66,763 $ 8.98 Restricted stock vested (87,513 ) $ 9.08 (62,251 ) $ 8.65 Restricted stock forfeited — $ — (5,000 ) $ 6.75 Outstanding at end of period 188,891 $ 9.52 66,513 $ 8.76 Expected to vest at end of period 188,891 $ 9.52 66,513 $ 8.76 Restricted stock that vested during 2020 and 2019 had a fair value of $734 and $535, respectively. Participants have the option to elect net settlement for restricted stock awards. Under net settlement, the Company withholds shares of stock that would otherwise be delivered to the employee and remits cash equal to the fair value of shares withheld to the taxing authority to satisfy tax withholding obligations. During 2020 and 2019, the Company withheld shares with a fair value of $28 and $68, respectively, related to the net settlement of restricted stock awards.

Concentration of Credit Risk

Concentration of Credit Risk	12 Months Ended
	Dec. 31, 2020
Risks And Uncertainties [Abstract]
Concentration of Credit Risk	Note 17. Concentration of Credit Risk During 2020 and 2019, the Company conducted a significant portion of its business with a limited number of customers, though not necessarily the same customers for each respective period. During 2020 and 2019, the Company’s five most significant customers represented 16.4% and 17.4% of total revenue, respectively. At December 31, 2020 and 2019, accounts receivable from the Company’s five most significant customers were $1,633

Other Expense - Net

Other Expense - Net	12 Months Ended
	Dec. 31, 2020
Other Income And Expenses [Abstract]
Other Expense – Net	Note 18. Other Expense – Net Other expense – net consisted of the following for the year ended December 31: 2020 2019 Interest income $ (23 ) $ (11 ) Foreign currency losses ̶ net 571 102 Other ̶ net 83 20 $ 631 $ 111

Segment and Geographic Informat

Segment and Geographic Information	12 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Segment and Geographic Information	Note 19. Segment and Geographic Information The Company manages its business globally in a singular operating segment in which it develops, manufactures and markets 3D printing machines, 3D printed and other products, materials and services. Geographically, the Company conducts its business through wholly-owned subsidiaries in the United States, Germany, and Japan. Geographic information for revenue was as follows (based on the country where the sale originated) for the year ended December 31: 2020 2019 United States $ 26,804 $ 20,897 Germany 24,217 20,966 Japan 8,232 11,413 $ 59,253 $ 53,276 Geographic information for long-lived assets was as follows (based on the physical location of assets) at December 31: 2020 2019 United States $ 12,176 $ 12,519 Germany 3,851 21,821 Japan 5,273 4,555 $ 21,300 $ 38,895 Refer to Note 8 and Note 11 for further discussion related to a sale-leaseback transaction associated with the Company’s European headquarters and operating facility in Gersthofen, Germany completed in February 2020 and the related impact on long-lived assets located in Germany during 2020.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2020
Subsequent Events [Abstract]
Subsequent Events	Note 20. Subsequent Events Termination of Canaccord Equity Distribution Agreement On February 9, 2021, the Company terminated the Canaccord Equity Distribution Agreement. At the time of the termination of the agreement, the remaining maximum offering capacity was $9,269. There were no fees or penalties incurred by the Company in connection with the termination of this agreement. Common Stock Offering On February 10, 2021, the Company entered into an underwriting agreement pursuant to which the Company agreed to issue and sell up to 1,666,667 shares of its common stock at a public offering price of $54.00 per share. In addition, the Company granted the underwriters a 30-day option to purchase up to an additional 205,907 shares of its common stock at the public offering price, less underwriting discounts and commissions. Under the agreement, the Company agreed to pay underwriting discounts and commissions of $2.835 per share, as well as reimburse the underwriters for certain expenses. On February 11, 2021, the underwriters exercised their option to purchase 205,907 shares of the Company’s stock in full. As a result of this common stock offering, during February 2021, the Company sold 1,872,574 shares of its common stock and received aggregate net proceeds to the Company of approximately $95,000 after underwriting discounts, commissions, legal and accounting fees, and other offering expenses payable by the Company. Extinguishment of Building Note Payable On February 26, 2021, the Company extinguished its building note payable (Note 14) in-full through cash payment of $1,199. The Company did not incur any prepayment penalties related to the extinguishment of the building note payable in advance of the maturity date (May 2027). At the extinguishment date, the net carrying amount of the building note payable was $1,185. As a result, the Company recognized a loss on the extinguishment of debt of $14, which represents the write-off of unamortized debt issuance costs, during the three months ended March 31, 2021. Termination of Related Party Revolving Credit Facility On March 5, 2021, the Company terminated the related party revolving credit facility (Note 13). There were no penalties associated with the Company’s termination of the related party revolving credit facility. Due to the termination, the Company accelerated the amortization of the remaining debt issuance costs associated with the related party revolving credit facility, resulting in recognition of a $105 loss on the extinguishment of debt during the three months ended March 31, 2021. The Company has evaluated all of its activities and concluded that no other subsequent events have occurred that would require recognition in the consolidated financial statements or disclosure in the notes to the consolidated financial statements, except as described above.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Organization	Organization The ExOne Company (“ExOne”) is a corporation organized under the laws of the state of Delaware. ExOne was formed on January 1, 2013, when The Ex One Company, LLC, a Delaware limited liability company, merged with and into a Delaware corporation, which survived and changed its name to The ExOne Company (the “Reorganization”). As a result of the Reorganization, The Ex One Company, LLC became ExOne, the common and preferred interest holders of The Ex One Company, LLC became holders of common stock and preferred stock, respectively, of ExOne, and the subsidiaries of The Ex One Company, LLC became the subsidiaries of ExOne. The consolidated financial statements include the accounts of ExOne, its wholly-owned subsidiaries, ExOne Americas LLC (United States); ExOne GmbH (Germany); ExOne Property GmbH (Germany); and ExOne KK (Japan). Collectively, the consolidated group is referred to as the “Company”. The Company filed a shelf registration statement on Form S-3 (No. 333-223690) with the Securities and Exchange Commission (“SEC”) on March 15, 2018. The purpose of the Form S-3 was to register various equity and debt securities. Subsidiaries of the Company are co-registrants with the Company (“Subsidiary Guarantors”), and the registration statement registered guarantees of debt securities by one or more of the Subsidiary Guarantors. The Subsidiary Guarantors are 100% owned by the Company and any guarantees by the Subsidiary Guarantors will be full and unconditional . Basis of Presentation The consolidated financial statements of the Company are prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). All material intercompany transactions and balances have been eliminated in consolidation. Certain amounts relating to operating lease right-of-use assets ($432), current portion of operating lease liabilities ($158) and operating lease liabilities – net of current portion ($274) in the accompanying consolidated balance sheet at December 31, 2019, have been reclassified from other noncurrent assets, accrued expenses and other current liabilities and other noncurrent liabilities, respectively, to conform to current period presentation.
Use of Estimates	Use of Estimates The preparation of these consolidated financial statements requires the Company to make certain judgments, estimates and assumptions regarding uncertainties that affect the reported amounts of assets, liabilities, revenue and expenses and related disclosure of contingent assets and liabilities. Areas that require significant judgments, estimates and assumptions include accounting for accounts receivable (including the allowance for doubtful accounts); inventories (including the allowance for slow-moving and obsolete inventories); product warranty reserves; contingencies; revenue (including the allocation of a sales contract’s total transaction price to each performance obligation for contracts with multiple performance obligations); and equity-based compensation (including the valuation of certain equity-based compensation awards issued by the Company). The Company bases its estimates on historical experience and on various other assumptions that are believed to be reasonable, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results may differ from these estimates.
Foreign Currency	Foreign Currency The local currency is the functional currency for significant operations outside of the United States. The determination of the functional currency of an operation is made based upon the appropriate economic and management indicators. Foreign currency assets and liabilities are translated into their United States dollar equivalents based upon year end exchange rates, and are included in stockholders’ equity as a component of other comprehensive income (loss). Revenues and expenses are translated at average exchange rates. Transaction gains and losses that arise from exchange rate fluctuations are charged to operations as incurred, except for gains and losses associated with certain long-term intercompany transactions between subsidiaries for which settlement is not planned or anticipated in the foreseeable future, which are included in other comprehensive income (loss) in the accompanying statement of consolidated operations and comprehensive loss. The Company transacts business globally and is subject to risks associated with fluctuating foreign exchange rates. For 2020 and 2019, 54.8% and 60.8% of the consolidated revenue of the Company was derived from transactions outside the United States, respectively. This revenue is generated primarily from wholly-owned subsidiaries operating in their respective countries and surrounding geographic areas. This revenue is primarily denominated in each subsidiary’s local functional currency, including the euro and Japanese yen.
Cash, Cash Equivalents, and Restricted Cash	Cash, Cash Equivalents, and Restricted Cash The Company considers all highly liquid instruments with maturities when purchased of three months or less to be cash equivalents. The Company’s policy is to invest cash in excess of short-term operating and debt-service requirements in such cash equivalents. These instruments are stated at cost, which approximates fair value because of the short maturity of the instruments. The Company maintains cash balances with financial institutions located in the United States, Germany and Japan. The Company places its cash with high quality financial institutions and believes its risk of loss is limited; however, at times, account balances may exceed international and federally insured limits. The Company has not experienced any losses associated with these cash balances. Restricted cash includes any cash balance held by the Company subject to restriction on withdrawal or use.
Inventories	Inventories The Company values all of its inventories at the lower of cost, as determined on the first-in, first-out method or net realizable value. Overhead is allocated to work in process and finished goods based upon normal capacity of the Company’s production facilities. Fixed overhead associated with production facilities that are being operated below normal capacity are recognized as a period expense rather than being capitalized as a product cost. An allowance for slow-moving and obsolete inventories is provided based on historical consumption experience, anticipated product demand and product design changes. These provisions reduce the cost basis of the respective inventories and are recorded as a charge to cost of sales.
Property and Equipment	Property and Equipment Property and equipment are recorded at cost and depreciated on a straight-line basis over the estimated useful lives of the related assets, generally three to forty years. Leasehold improvements are amortized on a straight-line basis over the shorter of the estimated useful life of the asset or the expected term of the related lease. Gains or losses from the sale of assets are recognized upon disposal or retirement of the related assets. Repairs and maintenance are charged to expense as incurred. The Company evaluates long-lived assets held and used for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets (asset group) may not be recoverable. Recoverability of assets is determined by comparing the estimated undiscounted net cash flows of the operations related to the assets (asset group) to their carrying amount. An impairment loss would be recognized when the carrying amount of the assets (asset group) exceeds the estimated undiscounted net cash flows. The amount of the impairment loss to be recorded is calculated as the excess of carrying value of assets (asset group) over their fair value. The determination of what constitutes an asset group, the associated undiscounted net cash flows, the fair value of assets (asset group) and the estimated useful lives of assets require significant judgments and estimates by management. No impairment loss related to held and used assets was recorded by the Company during 2020 or 2019.
Income Taxes	Income Taxes The provision (benefit) for income taxes is determined using the asset and liability approach of accounting for income taxes. Under this approach, the provision (benefit) for income taxes represents income taxes paid or payable (or received or receivable) for the current year plus the change in deferred taxes during the year. Deferred taxes represent the future tax consequences expected to occur when the reported amounts of assets and liabilities are recovered or paid and result from differences between the financial and tax bases of assets and liabilities and are adjusted for changes in tax rates and tax laws when enacted. Valuation allowances are established when necessary to reduce deferred tax assets to the amount expected to be realized. The Company’s foreign subsidiaries are taxed as corporations under the taxing regulations of those respective countries. As a result, the accompanying statement of consolidated operations and comprehensive loss includes a provision (benefit) for income taxes related to these foreign jurisdictions. Any undistributed earnings are intended to be permanently reinvested in the respective subsidiaries, with the exception of ExOne Property GmbH. The deferred taxes on the outside basis difference of the Company’s investment in ExOne Property GmbH were not significant at December 31, 2020. The Company recognizes the income tax benefit from an uncertain tax position only if it is more likely than not that the income tax position will be sustained on examination by the taxing authorities based upon the technical merits of the position. The income tax benefits recognized in the consolidated financial statements from such positions are then measured based upon the largest amount that has a greater than 50% likelihood of being realized upon settlement. Income tax benefits that do not meet the more likely than not criteria are recognized when effectively settled, which generally means that the statute of limitations has expired or that the appropriate taxing authority has completed its examination even though the statute of limitations remains open. Interest and penalties related to uncertain tax positions are recognized as part of the provision (benefit) for income taxes and are accrued beginning in the period that such interest and penalties would be applicable under relevant tax law until such time that the related income tax benefits are recognized.
Taxes on Revenue Producing Transactions	Taxes on Revenue Producing Transactions Taxes assessed by governmental authorities on revenue producing transactions, including sales, excise, value added and use taxes, are recorded on a net basis (excluded from revenue) in the accompanying statement of consolidated operations and comprehensive loss.
Research and Development	Research and Development The Company is involved in research and development of new methods and technologies relating to its products. Research and development expenses are charged to operations as they are incurred. The Company capitalizes the cost of certain materials, equipment and facilities that have alternative future uses in research and development projects or otherwise.
Advertising	Advertising Advertising costs are charged to expense as incurred and were not significant for 2020 or 2019.
Defined Contribution Plan	Defined Contribution Plan The Company sponsors a defined contribution savings plan under section 401(k) of the Internal Revenue Code. Under the plan, participating employees in the United States may elect to defer a portion of their pre-tax earnings, up to the Internal Revenue Service’s annual contribution limit. During 2020 and 2019, the Company made discretionary matching contributions of 50% of the first 8% of employee contributions, subject to certain Internal Revenue Service limitations. Discretionary matching contributions made by the Company during 2020 and 2019 were $307 and $304, respectively.
Equity-Based Compensation	Equity-Based Compensation The Company recognizes compensation expense for equity-based grants using the straight-line attribution method in which the expense is recognized ratably over the requisite service period based on the grant date fair value of the related award. Forfeitures of pre-vesting equity-based grants are recognized as they are incurred and result in an offset to equity-based compensation expense in the period of recognition. Fair value of equity-based awards is estimated on the date of grant using the Black-Scholes option pricing model.
Fair Value of Financial Instruments	Fair Value of Financial Instruments Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The Company measures the fair value of financial assets and liabilities according to a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value and requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs. The three levels of the fair value hierarchy are as follows: Level 1 inputs are quoted prices in active markets for identical assets or liabilities that are accessible at the measurement date; Level 2 inputs include inputs other than Level 1 that are observable, either directly or indirectly, and Level 3 inputs are unobservable inputs in which little or no market data exists, therefore typically reflect management’s estimates of assumptions that market participants would use in pricing the asset or liability. The hierarchy gives the highest priority to quoted prices in active markets for identical assets or liabilities (Level 1) and the lowest priority to measurements involving significant unobservable inputs (Level 3). At December 31, 2020 and December 31, 2019, the Company had no financial instruments (assets or liabilities) measured at fair value on a recurring basis.
COVID-19	COVID-19 In March 2020, the World Health Organization declared the novel strain of coronavirus a global pandemic (“COVID-19”) and recommended containment and mitigation measures worldwide. The impact of COVID-19 and the related economic, business and market disruptions were wide-ranging and continue to be significant. As a result of COVID-19, the Company was required to temporarily close its operations at its North Huntingdon, Pennsylvania facility for the period from March 23 through March 30, 2020. In response to COVID-19, the Company has incurred incremental costs associated with protecting the health and safety of the Company’s global workforce, enhanced sanitization of the Company’s global operating facilities, and information technology capabilities for employees operating remotely. Beginning in March 2020, restrictions imposed by various governmental authorities on both domestic and international shipping and travel have caused a disruption to the timing of delivery and installation of the Company’s 3D printing machines, resulting in negative impacts to the Company’s financial position, results of operations and cash flows. The duration and severity of the outbreak and its long-term impact on the Company’s business are uncertain at this time. The Company is unable to predict the impact that COVID-19 will have on its future financial position, results of operations and cash flows.
Recently Issued Accounting Guidance	Recently Issued Accounting Guidance The Company considers the applicability and impact of all Accounting Standards Updates (“ASUs”) issued by the Financial Accounting Standards Board (the “FASB”). Recently issued ASUs not listed below either were assessed and determined to be not applicable or are currently expected to have no impact on the consolidated financial statements of the Company. In June 2016, the FASB issued ASU 2016-13, “Financial Instruments – Credit Losses.” This ASU added a new impairment model (known as the current expected credit loss (“CECL”) model) that is based on expected losses rather than incurred losses. Under the new guidance, an entity recognizes as an allowance its estimate of expected credit losses. The CECL model applies to most debt instruments, trade receivables, lease receivables, financial guarantee contracts, and other loan commitments. The CECL model does not have a minimum threshold for recognition of impairment losses and entities will need to measure expected credit losses on assets that have a low risk of loss. As an SRC pursuant to Rule 12b-2 of the Exchange Act, these changes become effective for the Company on January 1, 2023. Management is currently evaluating the potential impact of these changes on the consolidated financial statements of the Company.
Loss Per Share	The Company presents basic and diluted loss per common share amounts. Basic loss per common share is calculated by dividing net loss available to common stockholders by the weighted average number of common shares outstanding during the applicable period. Diluted loss per common share is calculated by dividing net loss available to common stockholders by the weighted average number of common shares and common equivalent shares outstanding during the applicable period.
Revenue	The Company derives revenue from the sale of 3D printing machines and 3D printed and other products, materials and services. Revenue is recognized when the Company satisfies its performance obligation(s) under a contract (either implicit or explicit) by transferring the promised product or service to a customer, which is when (or as) the customer obtains control of the product or service. A performance obligation is a promise in a contract to transfer a distinct product or service to a customer. A contract’s transaction price is allocated to each distinct performance obligation. Revenue is measured as the amount of consideration the Company expects to receive in exchange for transferring products or providing services. As such, revenue is recorded net of returns, allowances, customer discounts, and incentives. Sales, value add, and other taxes collected from customers and remitted to governmental authorities are accounted for on a net (excluded from revenue) basis. Shipping and handling costs are included in cost of sales. Certain of the Company’s contracts with customers contain multiple performance obligations. Sales of 3D printing machines may also include optional equipment, materials, replacement components and services (installation, training and other services, including maintenance services and/or an extended warranty). Certain other contracts have a single performance obligation, as the promise to transfer products or services is not separately identifiable from other promises in the contract and, therefore, not distinct. For contracts with multiple performance obligations, the Company allocates the contract’s transaction price to each performance obligation using the Company’s best estimate of stand-alone selling price for each distinct product or service in the contract, which is generally based on an observable price.

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Loss (Tables)	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Summary of Changes in the Components of Accumulated Other Comprehensive Income (Loss)	The following table summarizes changes in the components of accumulated other comprehensive income (loss) for the periods indicated: For the years ended December 31, 2020 2019 Foreign currency translation adjustments Balance at beginning of period $ (11,483 ) $ (10,748 ) Other comprehensive income (loss) 1,345 (735 ) Balance at end of period $ (10,138 ) $ (11,483 )

Loss Per Share (Tables)

Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Computation of Basic and Diluted Loss Per Common Share	The information used to compute basic and diluted net loss per common share was as follows for the periods indicated: For the years ended December 31, 2020 2019 Net loss $ (14,924 ) $ (15,095 ) Weighted average shares outstanding (basic and diluted) 17,423,229 16,309,259 Net loss per common share: Basic $ (0.86 ) $ (0.93 ) Diluted $ (0.86 ) $ (0.93 )

Revenue (Tables)

Revenue (Tables)	12 Months Ended
	Dec. 31, 2020
Revenue From Contract With Customer [Abstract]
Summary of Revenue by Product Group	The following table summarizes the Company’s revenue by product group for the periods indicated: For the years ended December 31, 2020 2019 3D printing machines $ 31,470 $ 27,232 3D printed and other products, materials and services 27,783 26,044 $ 59,253 $ 53,276

Cash, Cash Equivalents, and R_2

Cash, Cash Equivalents, and Restricted Cash (Tables)	12 Months Ended
	Dec. 31, 2020
Cash And Cash Equivalents [Abstract]
Schedule of Reconciliation of Cash, Cash Equivalents and Restricted Cash	The following provides a reconciliation of cash, cash equivalents, and restricted cash as reported in the accompanying consolidated balance sheet to the same such amounts shown in the accompanying statement of consolidated cash flows at December 31: 2020 2019 Cash and cash equivalents $ 49,668 $ 5,265 Restricted cash 508 978 Cash, cash equivalents, and restricted cash $ 50,176 $ 6,243

Inventories (Tables)

Inventories (Tables)	12 Months Ended
	Dec. 31, 2020
Inventory Disclosure [Abstract]
Schedule of Inventories	Inventories consisted of the following at December 31: 2020 2019 Raw materials and components $ 9,436 $ 8,841 Work in process 4,797 4,922 Finished goods 6,329 6,007 $ 20,562 $ 19,770
Summary of Changes in Allowance for Slow-moving and Obsolete Inventories	The following table summarizes changes in the allowance for slow-moving and obsolete inventories for the periods indicated: 2020 2019 Balance at beginning of period $ 3,443 $ 4,143 Provision for slow-moving and obsolete inventories ̶ net 218 292 Reductions for physical disposal (sale or scrap) of previously reserved amounts (1,181 ) (914 ) Foreign currency translation adjustments 198 (78 ) Balance at end of period $ 2,678 $ 3,443

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2020
Long Lived Assets [Abstract]
Summary of Property and Equipment	Property and equipment consisted of the following at December 31: 2020 2019 Economic Life (in years) Land $ 3,494 $ 6,980 N/A Buildings and related improvements 10,246 25,675 5 - 40 Machinery and equipment 20,728 19,531 3 - 20 Other 6,291 7,086 3 - 20 40,759 59,272 Less: Accumulated depreciation (20,823 ) (21,478 ) 19,936 37,794 Construction-in-progress 1,364 1,101 Property and equipment ̶ net $ 21,300 $ 38,895

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities (Tables)	12 Months Ended
	Dec. 31, 2020
Payables And Accruals [Abstract]
Schedule of Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities consisted of the following at December 31: 2020 2019 Accrued license fees $ 1,563 $ 1,020 Product warranty reserves 1,335 866 Accrued payroll and related costs 1,089 1,382 Accrued professional fees 252 272 Income taxes payable 1 503 Deposit liability on sale of property and equipment — 2,243 Other 738 656 $ 4,978 $ 6,942

Product Warranty Reserves (Tabl

Product Warranty Reserves (Tables)	12 Months Ended
	Dec. 31, 2019
Product Warranties Disclosures [Abstract]
Summary of Changes in Product Warranty Reserves	The following table summarizes changes in product warranty reserves, which amounts were reflected in accrued expenses and other current liabilities in the accompanying consolidated balance sheet for the periods indicated: For the year ended December 31, 2020 2019 Balance at beginning of period $ 866 $ 1,670 Provisions for new issuances 1,318 1,125 Payments (1,920 ) (1,514 ) Reserve adjustments 1,033 (399 ) Foreign currency translation adjustments 38 (16 ) Balance at end of period $ 1,335 $ 866

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Schedule of Future Minimum Lease Payments of Operating Leases Arrangements	Future minimum lease payments of operating lease arrangements (with initial terms greater than 12 months) at December 31, 2020, were as follows: 2021 $ 2,119 2022 2,082 2023 48 2024 13 2025 2 Thereafter 1 Total minimum lease payments 4,265 Less: Present value discount (222 ) Total operating lease liabilities $ 4,043
Schedule of Supplemental Information Related to Operating Lease Arrangements	Supplemental information related to operating lease arrangements (with initial terms greater than 12 months) was as follows as of and for the year then ended December 31: 2020 2019 Right-of-use assets obtained in exchange for new operating lease liabilities $ 4,909 $ 209 Cash paid for amounts included in the measurement of operating lease liabilities $ 2,009 $ 198 Weighted average remaining lease term (in years) 2.1 3.1 Weighted average discount rate 5.1 % 5.5 %
Schedule of Operating and Sales-type Lease Arrangements	The Company recognized the following components under operating and sales-type lease arrangements in the accompanying statement of consolidated operations and comprehensive loss for the periods indicated: For the years ended December 31, 2020 2019 Operating Sales-type Operating Sales-type Revenue $ 785 $ — $ 1,523 $ — Interest income (a) $ — $ 62 $ — $ 94 (a) Interest income related to sales-type leases is recorded as a component of revenue in the accompanying statement of consolidated operations and comprehensive loss for each of the periods presented .
Schedule of Net Investment in Sales-type Leases	The Company’s net investment in sales-type leases consisted of the following at December 31: 2020 2019 Future minimum lease payments receivable $ 1,368 $ 1,595 Less: Allowance for doubtful accounts (463 ) (501 ) Net future minimum lease payments receivable 905 1,094 Less: Unearned interest income (167 ) (143 ) Net investment in sales-type leases $ 738 $ 951
Schedule of Future Minimum Lease Payment Receivable of Non-Cancellable Operating and Sales-type Lease	Future minimum lease payments of non-cancellable operating and sales-type lease arrangements as of December 31, 2020, were as follows: Operating Sales-type 2021 $ 414 $ 554 2022 — 390 2023 — 424 2024 — — 2025 — — Thereafter — — Total minimum lease payments $ 414 $ 1,368 Less: Allowance for doubtful accounts (463 ) Less: Present value discount (167 ) Future minimum lease payments receivable $ 738

Long-Term Debt (Tables)

Long-Term Debt (Tables)	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Components of Long-Term Debt	Long-term debt consisted of the following at December 31: 2020 2019 Principal Unamortized Debt Issuance Costs Net Principal Unamortized Debt Issuance Costs Net Paycheck Protection Program loan $ 2,194 $ — $ 2,194 $ — $ — $ — Building note payable 1,226 (15 ) 1,211 1,384 (20 ) 1,364 Less: Amount due within one year (1,626 ) 4 (1,622 ) (157 ) 4 (153 ) $ 1,794 $ (11 ) $ 1,783 $ 1,227 $ (16 ) $ 1,211
Future Maturities of Long-Term Debt	Future maturities of long-term debt at December 31, 2020, were as follows: 2021 $ 1,626 2022 912 2023 188 2023 195 2025 201 Thereafter 298 $ 3,420

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Schedule of Loss Before Tax	The components of loss before taxes were as follows: 2020 2019 United States $ (17,584 ) $ (16,452 ) Foreign 2,860 950 Loss before income taxes $ (14,724 ) $ (15,502 )
Summary of Income Tax (Benefit) Provision	The provision (benefit) for income taxes consisted of the following for year ended December 31: 2020 2019 Current Deferred Total Current Deferred Total United States $ 5 $ — $ 5 $ 4 $ — $ 4 Foreign — 195 195 (212 ) (199 ) (411 ) Provision (benefit) for income taxes $ 5 $ 195 $ 200 $ (208 ) $ (199 ) $ (407 )
Reconciliation of the Provision for Income Taxes	A reconciliation of the provision (benefit) for income taxes at the United States statutory rate to the effective rate of the Company for the years ended December 31 was as follows: 2020 2019 United States statutory rate (21%) $ (3,092 ) $ (3,255 ) Effect of foreign disregarded entity 329 (151 ) Taxes on foreign operations 76 64 Net change in valuation allowances 3,824 4,224 Reduction in uncertain tax positions — (818 ) Permanent differences (728 ) 83 Return to provision adjustments 133 (163 ) Deferred tax adjustments (291 ) (318 ) Other (51 ) (73 ) Provision (benefit) for income taxes $ 200 $ (407 ) Effective tax rate (1.4 )% 2.6 %
Components of Deferred Income Tax Assets and Liabilities	The components of deferred income tax assets and liabilities consisted of the following at December 31: 2020 2019 Deferred tax assets Accounts receivable $ 116 $ 110 Inventories 597 710 Accrued expenses and other current liabilities 1,352 477 Net operating loss carryforwards 32,582 27,710 Tax credit carryforwards 676 676 Other 961 1,968 Valuation allowance (34,881 ) (30,666 ) Total deferred tax assets 1,403 985 Deferred tax liabilities Property and equipment 539 690 Other 864 94 Total deferred tax liabilities 1,403 784 Net deferred tax assets (a) $ — $ 201 (a) At December 31, 2019, net deferred tax assets were reflected in other noncurrent assets in the accompanying consolidated balance sheet.
Summary of Changes to Valuation Allowances	The following table summarizes changes to the Company’s valuation allowances for the years ended December 31: 2020 2019 Balance at beginning of period $ 30,666 $ 26,563 Net increases in allowances 3,824 3,857 Net increases in net operating losses offset by uncertain tax positions — 368 Foreign currency translation adjustments 391 (122 ) Balance at end of period $ 34,881 $ 30,666
Reconciliation of Unrecognized Tax Benefits (Including Accrued Interest and Penalties)	A reconciliation of the beginning and ending amount of unrecognized tax benefits (including accrued interest and penalties) at December 31 was as follows: 2020 2019 Balance at beginning of period $ — $ 1,186 Additions based on tax positions related to the current year — — Additions for tax positions of prior years — 5 Reductions for tax positions of prior years — (1,186 ) Settlements — — Foreign currency translation adjustments — (5 ) Balance at end of period $ — $ —
Summary of Tax Years Subject to Examinations	The following table summarizes tax years remaining subject to examination for each of the Company’s subsidiaries at December 31, 2020: Jurisdiction Tax Years Remaining Subject to Examination United States 2017-2020 Germany 2016-2020 Japan 2018-2020 Italy 2015-2018

Equity-Based Compensation (Tabl

Equity-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Equity-Based Compensation Expense	The following table summarizes the total equity-based compensation expense recognized by the Company : 2020 2019 Equity-based compensation expense recognized: Stock options $ 417 $ 709 Restricted stock 790 696 Other (a) 18 11 Total equity-based compensation expense before income taxes 1,225 1,416 Benefit for income taxes (b) — — Total equity-based compensation expense net of income taxes $ 1,225 $ 1,416 (a) For both periods presented, Other represents expense associated with certain employee contractual amounts to be settled in equity. (b) The benefit for income taxes from equity-based compensation for each of the periods presented has been determined to be $0
Assumptions for Fair Value of Stock Options Granted Estimated on the Date of Grant Using the Black-Scholes Option	The fair value of stock options was estimated on the date of grant using the Black-Scholes option pricing model with the following assumptions: 2020 2019 Weighted average fair value per stock option $4.55 - $6.20 $2.51 - $3.68 Volatility 58.0% - 63.5% 53.3% - 60.1% Average risk-free interest rate 0.2% 1.5% - 2.5% Dividend yield 0.0% 0.0% Expected term (years) 2.5 - 3.5 2.5 - 3.5
Summary of Activity for Stock Options	The activity for stock options was as follows for the year ended December 31: 2020 2019 Number Options Weighted Exercise Price Weighted Average Grant Date Fair Value Number Options Weighted Exercise Price Weighted Average Grant Date Fair Value Outstanding at beginning of period 854,259 $ 9.34 $ 4.49 621,986 $ 10.66 $ 5.52 Stock options granted 28,188 $ 14.12 $ 5.83 319,310 $ 7.34 $ 2.94 Stock options exercised (127,854 ) $ 7.30 $ 3.12 (40,432 ) $ 7.17 $ 3.03 Stock options forfeited (81,186 ) $ 7.83 $ 3.40 (9,773 ) $ 7.67 $ 3.70 Stock options expired (32,175 ) $ 12.94 $ 7.44 (36,832 ) $ 16.94 $ 10.35 Outstanding at end of period 641,232 $ 9.80 $ 4.74 854,259 $ 9.34 $ 4.49 Exercisable at end of period 502,260 $ 10.40 $ 5.21 494,884 $ 10.85 $ 5.59 Expected to vest at end of period 138,972 $ 7.65 $ 3.01 359,375 $ 7.27 $ 2.96
Summary of Activity for Restricted Stock Awards	The activity for restricted stock was as follows for the year ended December 31: 2020 2019 Shares of Restricted Stock Weighted Average Grant Date Fair Value Shares of Restricted Stock Weighted Average Grant Date Fair Value Outstanding at beginning of period 66,513 $ 8.76 67,001 $ 8.30 Restricted stock granted 209,891 $ 9.58 66,763 $ 8.98 Restricted stock vested (87,513 ) $ 9.08 (62,251 ) $ 8.65 Restricted stock forfeited — $ — (5,000 ) $ 6.75 Outstanding at end of period 188,891 $ 9.52 66,513 $ 8.76 Expected to vest at end of period 188,891 $ 9.52 66,513 $ 8.76

Other Expense - Net (Tables)

Other Expense - Net (Tables)	12 Months Ended
	Dec. 31, 2020
Other Income And Expenses [Abstract]
Schedule of Other Expense - Net	Other expense – net consisted of the following for the year ended December 31: 2020 2019 Interest income $ (23 ) $ (11 ) Foreign currency losses ̶ net 571 102 Other ̶ net 83 20 $ 631 $ 111

Segment and Geographic Inform_2

Segment and Geographic Information (Tables)	12 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Geographic Information for Revenue	Geographic information for revenue was as follows (based on the country where the sale originated) for the year ended December 31: 2020 2019 United States $ 26,804 $ 20,897 Germany 24,217 20,966 Japan 8,232 11,413 $ 59,253 $ 53,276
Geographic Information for Long-Lived Assets	Geographic information for long-lived assets was as follows (based on the physical location of assets) at December 31: 2020 2019 United States $ 12,176 $ 12,519 Germany 3,851 21,821 Japan 5,273 4,555 $ 21,300 $ 38,895

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Entity Incorporation, State or Country Code	DE
Date of incorporation	Jan. 1, 2013
Operating lease liabilities - net of current portion	$ 2,085,000	$ 274,000
Operating lease right-of-use assets	4,043,000	432,000
Current portion of operating lease liabilities	$ 1,958,000	158,000
Maturity of liquid instruments when purchased	three months or less
Long-lived assets held for use impairment loss	$ 0	0
Tax benefits recognized upon settlement	50.00%
Advertising costs	$ 0	$ 0
Percentage of contributions matched	50.00%	50.00%
Percentage of matching contributions	8.00%	8.00%
Contributions made to defined contribution savings plan	$ 307,000	$ 304,000
Maximum [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Estimated useful lives	40 years
Minimum [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Estimated useful lives	3 years
Geographic Concentration Risk [Member] | Sales Revenue, Net [Member] | Outside of United States [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Percentage of revenue derived outside the United States	54.80%	60.80%
Subsidiary Guarantors [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Percentage of ownership in subsidiary guarantors	100.00%

Common Stock Offerings - Additi

Common Stock Offerings - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended	9 Months Ended	12 Months Ended
	Jun. 30, 2020	Sep. 30, 2020	Dec. 31, 2020
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Incurred expenses			$ 340
Unpaid incurred expenses			171
Accounts Payable [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Unpaid incurred expenses			$ 171
Equity Distribution Agreement Oppenheimer and Company [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Sale of stock, consideration received on transaction	$ 25,000
Commission on sale of common stock	3.00%
Sale of stock, number of shares issued in transaction			2,204,875
Canaccord Equity Distribution Agreement [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Sale of stock, consideration received on transaction		$ 25,000
Commission on sale of common stock		3.00%
Sale of stock, number of shares issued in transaction			1,240,510
Oppenheimer and Canaccord Equity Distribution Agreement [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Sale of stock, number of shares issued in transaction			3,445,385
Sale of stock, price per share			$ 11.82
Proceeds from stock plans			$ 39,509

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Loss - Summary of Changes in the Components of Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Statement Of Income And Comprehensive Income [Abstract]
Balance at beginning of period	$ (11,483)	$ (10,748)
Other comprehensive income (loss)	1,345	(735)
Balance at end of period	$ (10,138)	$ (11,483)

Accumulated Other Comprehensi_4

Accumulated Other Comprehensive Loss - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Statement Of Income And Comprehensive Income [Abstract]
Accumulated other comprehensive loss, tax	$ 0	$ 0
Amounts reclassified to earnings from accumulated other comprehensive loss	$ 0	$ 0

Loss Per Share - Additional Inf

Loss Per Share - Additional Information (Detail) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Stock Option [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential shares of anti-dilutive common stock	641,232	854,259
Restricted Stock [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential shares of anti-dilutive common stock	188,891	66,513

Loss Per Share - Computation of

Loss Per Share - Computation of Basic and Diluted Loss Per Common Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Earnings Per Share [Abstract]
Net loss	$ (14,924)	$ (15,095)
Weighted average shares outstanding (basic and diluted)	17,423,229	16,309,259
Net loss per common share:
Basic	$ (0.86)	$ (0.93)
Diluted	$ (0.86)	$ (0.93)

Revenue - Summary of Revenue by

Revenue - Summary of Revenue by Product Group (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Revenue from External Customer [Line Items]
Revenue	$ 59,253	$ 53,276
3D Printing Machines [Member]
Revenue from External Customer [Line Items]
Revenue	31,470	27,232
3D Printed and Other Products, Materials and Services [Member]
Revenue from External Customer [Line Items]
Revenue	$ 27,783	$ 26,044

Revenue - Additional Informatio

Revenue - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Disaggregation Of Revenue [Line Items]
Revenue, description of payment terms	the Company’s terms of sale generally require payment within 30 to 60 days after delivery, although the Company also recognizes that longer payment periods are customary in certain countries where it transacts business.
Revenue recognized related to contract liabilities	$ 9,343
Customer prepayment		$ 2,241
Revenue, remaining performance obligation	39,400
Allowance for doubtful accounts	576	508
Provisions for bad debts, net	$ 23	$ 279
Minimum [Member]
Disaggregation Of Revenue [Line Items]
Term till payment is required from date of shipment	30 days
Maximum [Member]
Disaggregation Of Revenue [Line Items]
Term till payment is required from date of shipment	60 days

Revenue - Additional Informat_2

Revenue - Additional Information (Detail 1) $ in Thousands	Dec. 31, 2020USD ($)
Disaggregation Of Revenue [Line Items]
Revenue, remaining performance obligation	$ 39,400
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2020-01-01
Disaggregation Of Revenue [Line Items]
Revenue, remaining performance obligation	$ 33,000
Revenue, remaining performance obligation, Expected timing of satisfaction, period	12 months

Cash, Cash Equivalents, and R_3

Cash, Cash Equivalents, and Restricted Cash - Schedule of Reconciliation of Cash, Cash Equivalents, and Restricted Cash (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Cash And Cash Equivalents [Abstract]
Cash and cash equivalents	$ 49,668	$ 5,265
Restricted cash	508	978
Cash, cash equivalents, and restricted cash	$ 50,176	$ 6,243

Cash, Cash Equivalents, and R_4

Cash, Cash Equivalents, and Restricted Cash - Additional Information (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Cash Cash Equivalents And Restricted Cash [Line Items]
Restricted cash associated with cash collateral	$ 508	$ 978
United States Bank [Member]
Cash Cash Equivalents And Restricted Cash [Line Items]
Restricted cash associated with cash collateral	$ 508	508
German Bank [Member]
Cash Cash Equivalents And Restricted Cash [Line Items]
Restricted cash associated with cash collateral		$ 470

Inventories - Schedule of Inven

Inventories - Schedule of Inventories (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Inventory Disclosure [Abstract]
Raw materials and components	$ 9,436	$ 8,841
Work in process	4,797	4,922
Finished goods	6,329	6,007
Inventories	$ 20,562	$ 19,770

Inventories - Additional Inform

Inventories - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Inventory [Line Items]
Allowance for slow-moving and obsolete inventories	$ 2,678	$ 3,443	$ 4,143
Inventories [Member]
Inventory [Line Items]
Inventory (credit) charge	$ 205

Inventories - Summary of Change

Inventories - Summary of Changes in Allowance for Slow-moving and Obsolete Inventories (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Inventory Disclosure [Abstract]
Balance at beginning of period	$ 3,443	$ 4,143
Provision for slow-moving and obsolete inventories ̶ net	218	292
Reductions for physical disposal (sale or scrap) of previously reserved amounts	(1,181)	(914)
Foreign currency translation adjustments	198	(78)
Balance at end of period	$ 2,678	$ 3,443

Property and Equipment - Summar

Property and Equipment - Summary of Property and Equipment (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Total gross property and equipment before accumulated depreciation	$ 40,759	$ 59,272
Less: Accumulated depreciation	(20,823)	(21,478)
Property and equipment, excluding construction-in-progress	19,936	37,794
Construction-in-progress	1,364	1,101
Property and equipment ̶ net	$ 21,300	38,895
Minimum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, Economic Life	3 years
Minimum [Member] | Building and Related Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, Economic Life	5 years
Minimum [Member] | Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, Economic Life	3 years
Minimum [Member] | Other [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, Economic Life	3 years
Maximum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, Economic Life	40 years
Maximum [Member] | Building and Related Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, Economic Life	40 years
Maximum [Member] | Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, Economic Life	20 years
Maximum [Member] | Other [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, Economic Life	20 years
Land [Member]
Property, Plant and Equipment [Line Items]
Total gross property and equipment before accumulated depreciation	$ 3,494	6,980
Building and Related Improvements [Member]
Property, Plant and Equipment [Line Items]
Total gross property and equipment before accumulated depreciation	10,246	25,675
Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Total gross property and equipment before accumulated depreciation	20,728	19,531
Other [Member]
Property, Plant and Equipment [Line Items]
Total gross property and equipment before accumulated depreciation	$ 6,291	$ 7,086

Property and Equipment - Additi

Property and Equipment - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Machinery and equipment		$ 40,759	$ 59,272
Carrying value of assets		21,300	38,895
Depreciation		3,775	4,581
Derecognized net property and equipment	$ 17,282
Gain on sale of facility	$ 1,462	1,462
Machinery and Equipment under Finance Lease [Member]
Property, Plant and Equipment [Line Items]
Machinery and equipment		142	63
Machinery and Equipment under Operating Lease [Member]
Property, Plant and Equipment [Line Items]
Machinery and equipment		1,920	1,309
Carrying value of assets		$ 986	$ 426

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses and Other Current Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Payables And Accruals [Abstract]
Accrued license fees	$ 1,563	$ 1,020
Product warranty reserves	1,335	866
Accrued payroll and related costs	1,089	1,382
Accrued professional fees	252	272
Income taxes payable	1	503
Deposit liability on sale of property and equipment		2,243
Other	738	656
Accrued expenses and other current liabilities	$ 4,978	$ 6,942

Product Warranty Reserves - Add

Product Warranty Reserves - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2020
Product Warranties Disclosures [Abstract]
Standard product warranty period	Substantially all of the Company’s 3D printing machines are covered by a standard one-year warranty. Generally, at the time of sale, a liability is recorded (with an offset to cost of sales) based upon the expected cost of replacement parts and labor to be incurred over the life of the standard warranty.

Product Warranty Reserves - Sum

Product Warranty Reserves - Summary of Changes in Product Warranty Reserves (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Guarantees [Abstract]
Balance at beginning of period	$ 866	$ 1,670
Provisions for new issuances	1,318	1,125
Payments	(1,920)	(1,514)
Reserve adjustments	1,033	(399)
Foreign currency translation adjustments	38	(16)
Balance at end of period	$ 1,335	$ 866

Leases - Additional Information

Leases - Additional Information (Detail) € in Thousands	Dec. 10, 2019USD ($)RenewalOption	Dec. 10, 2019EUR (€)RenewalOption	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Dec. 10, 2019EUR (€)
Leases [Line Items]
Lease expiration year			2026
Lease cost			$ 2,115,000	$ 389,000
Short term lease cost			126,000	189,000
Operating lease right-of-use asset			4,043,000	432,000
Operating lease liability			4,043,000
Provision for bad debt lease			$ 0	$ 416,000
Minimum [Member]
Leases [Line Items]
Operating lease arrangement terms			1 year
Maximum [Member]
Leases [Line Items]
Operating lease arrangement terms			5 years
Germany [Member] | Purchase Agreement [Member] | Sale-Leaseback of Gersthofen, Germany Facility [Member]
Leases [Line Items]
Purchase price from sale leaseback	$ 18,500,000				€ 17,000
Proceeds from sale leaseback	2,200,000	€ 2,000
Sale leaseback annual rent	$ 1,700,000	€ 1,500
Sale leaseback transaction, lease terms			Concurrent with the execution of the Purchase Agreement, ExOne GmbH and the Buyer entered into a rental contract (the “Lease”) for the leaseback of the Facility for an initial aggregate annual rent totaling approximately $1,700 (€1,500), plus applicable taxes, which is fixed during the initial three-year term and is subject to adjustment on an annual basis (in accordance with the consumer price index for Germany) during the two five-year option extension periods
Sale leaseback, term of contract	3 years	3 years
Number of renewal option for sale leaseback | RenewalOption	2	2
Sale lease back renewal term	5 years	5 years
Sale-leaseback transaction closed date	February 18, 2020	February 18, 2020
Operating lease right-of-use asset	$ 4,605
Operating lease liability	$ 4,605

Leases - Schedule of Future Min

Leases - Schedule of Future Minimum Lease Payments of Operating Leases Arrangements (Detail) $ in Thousands	Dec. 31, 2020USD ($)
Leases [Abstract]
2021	$ 2,119
2022	2,082
2023	48
2024	13
2025	2
Thereafter	1
Total minimum lease payments	4,265
Less: Present value discount	(222)
Total operating lease liabilities	$ 4,043

Leases - Schedule of Supplement

Leases - Schedule of Supplemental Information Related to Operating Lease Arrangements (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 4,909	$ 209
Cash paid for amounts included in the measurement of operating lease liabilities	$ 2,009	$ 198
Weighted average remaining lease term (in years)	2 years 1 month 6 days	3 years 1 month 6 days
Weighted average discount rate	5.10%	5.50%

Leases - Schedule of Operating

Leases - Schedule of Operating and Sales-type Lease Arrangements (Detail) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Operating lease revenue		$ 785	$ 1,523
Sales-type lease interest income	[1]	$ 62	$ 94
[1]	Interest income related to sales-type leases is recorded as a component of revenue in the accompanying statement of consolidated operations and comprehensive loss for each of the periods presented .

Leases - Schedule of Net Invest

Leases - Schedule of Net Investment in Sales-type Leases (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Future minimum lease payments receivable	$ 1,368
Less: Allowance for doubtful accounts	(463)
Net future minimum lease payments receivable	905
Less: Unearned interest income	(167)
Net investment in sales-type leases	$ 738
Future minimum lease payments receivable		$ 1,595
Less: Allowance for doubtful accounts		(501)
Net future minimum lease payments receivable		1,094
Less: Unearned interest income		(143)
Net investment in sales-type leases		$ 951

Leases - Schedule of Future M_2

Leases - Schedule of Future Minimum Lease Payment Receivable of Non-Cancellable Operating and Sales-type Lease (Details) $ in Thousands	Dec. 31, 2020USD ($)
Operating lease arrangements
2021	$ 414
Total minimum lease payments	414
Sales-type lease arrangements
2021	554
2022	390
2023	424
Total minimum lease payments	1,368
Less: Allowance for doubtful accounts	(463)
Less: Present value discount	(167)
Future minimum lease payments receivable	$ 738

Contingencies and Commitments -

Contingencies and Commitments - Additional Information (Detail) - Amended GmbH Credit Agreement [Member] - Financial Guarantees and Letters of Credit [Member] € in Thousands, $ in Thousands	Feb. 24, 2020USD ($)	Feb. 24, 2020EUR (€)	Dec. 31, 2020USD ($)	Dec. 31, 2020EUR (€)	Dec. 31, 2019USD ($)	Dec. 31, 2019EUR (€)
Line Of Credit Facility [Line Items]
Line of credit facility, increased capacity amount	$ 4,300	€ 3,500
German Bank [Member]
Line Of Credit Facility [Line Items]
Credit facility, outstanding amount					$ 560	€ 499
Debt expiration dates range start			Mar. 31, 2021
Debt expiration dates range end			Dec. 31, 2021
German Bank [Member] | Commercial Transactions Requiring Security [Member]
Line Of Credit Facility [Line Items]
Credit facility, outstanding amount			$ 928	€ 756
Minimum [Member] | German Bank [Member]
Line Of Credit Facility [Line Items]
Issuance of financial guarantees and letters of credit	1,200	1,000
Maximum [Member] | Cash Collateral [Member] | German Bank [Member]
Line Of Credit Facility [Line Items]
Issuance of financial guarantees and letters of credit	$ 1,200	€ 1,000

Related Party Revolving Credi_2

Related Party Revolving Credit Facility - Additional Information (Detail) - USD ($)	Feb. 18, 2020	Mar. 12, 2018	Dec. 31, 2020	Dec. 31, 2019
Related Party Transaction [Line Items]
Amortization of debt issuance costs			$ 49,000	$ 93,000
LBM Holdings, LLC [Member] | Revolving Credit Facility [Member]
Related Party Transaction [Line Items]
Line of credit facility, maximum borrowing capacity		$ 15,000,000
Credit facility, expiration period		3 years
Credit facility, expiration date		Mar. 12, 2021
Credit facility, description of variable rate basis			one-month LIBOR
Credit facility, interest rate			5.10%	6.80%
Credit facility, commitment fee on unused portion, percentage		0.75%
Credit facility, commitment fee on unused portion, payable term			The Credit Agreement required a commitment fee of 75 basis points, or 0.75%, on the unused portion of the facility, payable monthly in arrears.
Credit facility, up-front commitment fee percentage		1.25%
Credit facility, up-front commitment fee amount		$ 188,000
Credit facility, minimum increments		$ 1,000,000
Credit facility, borrowings			$ 0
Repaid borrowed amount				$ 4,000,000
Debt issuance costs, gross			265,000
Interest expense relating to the Credit Agreement			147,000	260,000
Amortization of debt issuance costs			44,000
Debt issuance costs, net			111,000
Interest expense related to commitment fee			103,000
Accounts payable			9,000	$ 28,000
LBM Holdings, LLC [Member] | Revolving Credit Facility [Member] | Prepaid Expenses and Other Current Assets [Member]
Related Party Transaction [Line Items]
Debt issuance costs, net			35,000
LBM Holdings, LLC [Member] | Revolving Credit Facility [Member] | Other Noncurrent Assets [Member]
Related Party Transaction [Line Items]
Debt issuance costs, net			76,000
LBM Holdings, LLC [Member] | Revolving Credit Facility [Member] | London Interbank Offered Rate (LIBOR) [Member]
Related Party Transaction [Line Items]
Credit facility, basis spread on variable rate		5.00%
LBM Holdings, LLC [Member] | Amended Revolving Credit Facility [Member]
Related Party Transaction [Line Items]
Line of credit facility, maximum borrowing capacity	$ 10,000,000
Credit facility, expiration date	Mar. 31, 2024
Credit facility, commitment fee on unused portion, percentage	1.00%
Debt issuance costs, gross			$ 49,000

Long-Term Debt - Components of

Long-Term Debt - Components of Long-Term Debt (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Debt Disclosure [Abstract]
Paycheck Protection Program loan	$ 2,194
Building note payable, Principal	1,226	$ 1,384
Less: amount due within one year, Principal	(1,626)	(157)
Long-term debt - net of current portion, Principal	1,794	1,227
Building note payable, Unamortized Debt Issuance Costs	(15)	(20)
Less: amount due within one year, Unamortized Debt Issuance Costs	4	4
Long-term debt - net of current portion, Unamortized Debt Issuance Costs	(11)	(16)
Paycheck Protection Program loan	2,194
Building note payable, Net	1,211	1,364
Less: amount due within one year, Net	(1,622)	(153)
Long-term debt - net of current portion	$ 1,783	$ 1,211

Long-Term Debt - Additional Inf

Long-Term Debt - Additional Information (Detail) - USD ($) $ in Thousands	Apr. 18, 2020	Dec. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Long term debt fair value		$ 3,382	$ 1,384
Building Note Payable [Member]
Debt Instrument [Line Items]
Notes payable monthly payments		$ 18
Building note payable, with monthly payments interest rate		4.00%
Building note payable, with monthly payments basis spread		3.25%
Date of interest rate adjustment		2017-05
Notes payable maturity		2027-05
Building Note Payable [Member] | Building [Member] | North Huntington, Pennsylvania [Member]
Debt Instrument [Line Items]
Carrying value of collateralized facility		$ 4,795
Building Note Payable [Member] | United States Treasury Securities [Member]
Debt Instrument [Line Items]
Notes payable monthly payments		$ 19
Paycheck Protection Program [Member]
Debt Instrument [Line Items]
Loan bears interest rate	1.00%	1.00%
Maturity date	Apr. 18, 2022
Lender [Member] | Paycheck Protection Program [Member]
Debt Instrument [Line Items]
Loan principal amount		$ 2,194

Long-Term Debt - Future Maturit

Long-Term Debt - Future Maturities of Long-Term Debt (Detail) $ in Thousands	Dec. 31, 2020USD ($)
Debt Disclosure [Abstract]
2021	$ 1,626
2022	912
2023	188
2023	195
2025	201
Thereafter	298
Long-term debt	$ 3,420

Income Taxes - Schedule of Loss

Income Taxes - Schedule of Loss Before Tax (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
United States	$ (17,584)	$ (16,452)
Foreign	2,860	950
Loss before income taxes	$ (14,724)	$ (15,502)

Income Taxes - Summary of Incom

Income Taxes - Summary of Income Tax (Benefit) Provision (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
United States	$ 5	$ 4
Foreign		(212)
Provision (benefit) for income taxes	5	(208)
Foreign	195	(199)
Provision (benefit) for income taxes	195	(199)
United States	5	4
Foreign	195	(411)
Provision (benefit) for income taxes	$ 200	$ (407)

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of the Provision for Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
United States statutory rate (21%)	$ (3,092)	$ (3,255)
Effect of foreign disregarded entity	329	(151)
Taxes on foreign operations	76	64
Net change in valuation allowances	3,824	4,224
Reduction in uncertain tax positions		(818)
Permanent differences	(728)	83
Return to provision adjustments	133	(163)
Deferred tax adjustments	(291)	(318)
Other	(51)	(73)
Provision (benefit) for income taxes	$ 200	$ (407)
Effective tax rate	(1.40%)	2.60%

Income Taxes - Reconciliation_2

Income Taxes - Reconciliation of the Provision for Income Taxes (Parenthetical) (Detail)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
United States statutory rate	21.00%	21.00%

Income Taxes - Components of De

Income Taxes - Components of Deferred Income Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets
Accounts receivable		$ 116	$ 110
Inventories		597	710
Accrued expenses and other current liabilities		1,352	477
Net operating loss carryforwards		32,582	27,710
Tax credit carryforwards		676	676
Other		961	1,968
Valuation allowance		(34,881)	(30,666)	$ (26,563)
Total deferred tax assets		1,403	985
Deferred tax liabilities
Property and equipment		539	690
Other		864	94
Total deferred tax liabilities		$ 1,403	784
Net deferred tax assets	[1]		$ 201
[1]	At December 31, 2019, net deferred tax assets were reflected in other noncurrent assets in the accompanying consolidated balance sheet.

Income Taxes - Summary of Chang

Income Taxes - Summary of Changes to Valuation Allowances (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Balance at beginning of period	$ 30,666	$ 26,563
Net increases in allowances	3,824	3,857
Net increases in net operating losses offset by uncertain tax positions		368
Foreign currency translation adjustments	391	(122)
Balance at end of period	$ 34,881	$ 30,666

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Jan. 31, 2019
Schedule Of Income Taxes [Line Items]
Penalties and interest expense	$ 0	$ 0
Subsidiaries [Member] | United States [Member]
Schedule Of Income Taxes [Line Items]
Net operating loss carryforwards	115,285,000
Net operating loss carryforwards subject to expire	70,761,000
Subsidiaries [Member] | Japan [Member]
Schedule Of Income Taxes [Line Items]
Net operating loss carryforwards	2,549,000
Subsidiaries [Member] | Germany [Member]
Schedule Of Income Taxes [Line Items]
Net operating loss carryforwards	$ 24,450,000
Subsidiaries [Member] | Germany [Member] | Local Taxing Authorities [Member]
Schedule Of Income Taxes [Line Items]
Reversal of previously recorded liabilities for uncertain tax positions		111,000	$ 1,075,000
Uncertain tax positions expected amount to be offset against net operating loss carryforwards		$ 111,000	$ 257,000
Subsidiaries [Member] | Earliest Tax Year [Member] | United States [Member]
Schedule Of Income Taxes [Line Items]
Expiration period of net operating loss carryforwards	2033
Subsidiaries [Member] | Earliest Tax Year [Member] | Japan [Member]
Schedule Of Income Taxes [Line Items]
Expiration period of net operating loss carryforwards	2022
Subsidiaries [Member] | Latest Tax Year [Member] | United States [Member]
Schedule Of Income Taxes [Line Items]
Expiration period of net operating loss carryforwards	2037
Subsidiaries [Member] | Latest Tax Year [Member] | Japan [Member]
Schedule Of Income Taxes [Line Items]
Expiration period of net operating loss carryforwards	2026
Subsidiaries [Member] | 2023 [Member] | Local Taxing Authorities [Member]
Schedule Of Income Taxes [Line Items]
Net operating loss carryforwards	$ 11,567,000
Subsidiaries [Member] | 2023 [Member] | United States [Member]
Schedule Of Income Taxes [Line Items]
Tax credit carryforwards	$ 676,000
Expiration period of tax credit carryforwards	2023

Income Taxes - Reconciliation_3

Income Taxes - Reconciliation of Unrecognized Tax Benefits (Including Accrued Interest and Penalties) (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
Income Tax Disclosure [Abstract]
Balance at beginning of period	$ 1,186
Additions for tax positions of prior years	5
Reductions for tax positions of prior years	(1,186)
Foreign currency translation adjustments	$ (5)

Income Taxes - Summary of Tax Y

Income Taxes - Summary of Tax Year Subject to Examinations (Detail)	12 Months Ended
	Dec. 31, 2020
United States [Member] | Earliest Tax Year [Member]
Income Tax Contingency [Line Items]
Tax year subject to examination	2017
United States [Member] | Latest Tax Year [Member]
Income Tax Contingency [Line Items]
Tax year subject to examination	2020
Germany [Member] | Earliest Tax Year [Member]
Income Tax Contingency [Line Items]
Tax year subject to examination	2016
Germany [Member] | Latest Tax Year [Member]
Income Tax Contingency [Line Items]
Tax year subject to examination	2020
Japan [Member] | Earliest Tax Year [Member]
Income Tax Contingency [Line Items]
Tax year subject to examination	2018
Japan [Member] | Latest Tax Year [Member]
Income Tax Contingency [Line Items]
Tax year subject to examination	2020
Italy [Member] | Earliest Tax Year [Member]
Income Tax Contingency [Line Items]
Tax year subject to examination	2015
Italy [Member] | Latest Tax Year [Member]
Income Tax Contingency [Line Items]
Tax year subject to examination	2018

Equity-Based Compensation - Add

Equity-Based Compensation - Additional Information (Detail) - USD ($)	Jan. 24, 2013	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense		$ 1,225,000	$ 1,416,000
Issuance of vested common stock		20,009,157	16,346,960
Weighted-average remaining vesting period		2 years 3 months 18 days
Proceeds from exercise of employee stock options		$ 934,000	$ 289,000
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense		417,000	709,000
Total future compensation expense		295,000
Intrinsic value, stock options exercisable				$ 493,000
Intrinsic value, stock options expected to vest		$ 306,000
Weighted average remaining contractual term of stock options exercisable		3 years 1 month 6 days
Weighted average remaining contractual term of stock options expected to vest		3 years 8 months 12 days
Intrinsic value of stock options exercised		$ 1,222,000	358,000
Proceeds from exercise of employee stock options		934,000	289,000
Income tax benefit		0	0
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense		790,000	696,000
Total future compensation expense		1,364,000
Fair value of restricted shares vested		734,000	535,000
Fair value of shares withtheld		$ 28,000	68,000
Maximum [Member] | Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		3 years
Stock options contractual expiration period		10 years
Maximum [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		3 years
Minimum [Member] | Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		1 year
Stock options contractual expiration period		5 years
Minimum [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		1 year
2013 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for issuance	500,000
Remaining shares available for future issuances		499,189
2013 Equity Incentive Plan [Member] | Common Stock [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of outstanding shares of common stock	3.00%
Number of Shares authorized	1,992,241
2019 Annual Incentive Program [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense			$ 0
Issuance of vested common stock			0
2020 Annual Incentive Program [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense		$ 0
Issuance of vested common stock		0

Equity-Based Compensation - Sum

Equity-Based Compensation - Summary of Equity-Based Compensation Expense (Detail) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019
Equity-based compensation expense recognized:
Total equity-based compensation expense before income taxes		$ 1,225	$ 1,416
Benefit for income taxes	[1]	0	0
Total equity-based compensation expense net of income taxes		1,225	1,416
Stock Options [Member]
Equity-based compensation expense recognized:
Total equity-based compensation expense before income taxes		417	709
Restricted Stock [Member]
Equity-based compensation expense recognized:
Total equity-based compensation expense before income taxes		790	696
Other [Member]
Equity-based compensation expense recognized:
Total equity-based compensation expense before income taxes	[2]	$ 18	$ 11
[1]	The benefit for income taxes from equity-based compensation for each of the periods presented has been determined to be $0
[2]	For both periods presented, Other represents expense associated with certain employee contractual amounts to be settled in equity.

Equity-Based Compensation - S_2

Equity-Based Compensation - Summary of Equity-Based Compensation Expense (Parenthetical) (Detail) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Benefit for income taxes from equity-based compensation	[1]	$ 0	$ 0
[1]	The benefit for income taxes from equity-based compensation for each of the periods presented has been determined to be $0

Equity-Based Compensation - Ass

Equity-Based Compensation - Assumptions for Fair Value of Stock Options Granted Estimated on the Date of Grant Using the Black-Scholes Option (Detail) - Stock Options [Member] - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Average risk-free interest rate	0.20%
Dividend yield	0.00%	0.00%
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average fair value per stock option	$ 4.55	$ 2.51
Volatility	58.00%	53.30%
Average risk-free interest rate		1.50%
Expected term (years)	2 years 6 months	2 years 6 months
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average fair value per stock option	$ 6.20	$ 3.68
Volatility	63.50%	60.10%
Average risk-free interest rate		2.50%
Expected term (years)	3 years 6 months	3 years 6 months

Equity-Based Compensation - S_3

Equity-Based Compensation - Summary of Activity for Stock Options (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock options outstanding, Beginning balance	854,259	621,986
Stock options granted	28,188	319,310
Stock options exercised	(127,854)	(40,432)
Stock options forfeited	(81,186)	(9,773)
Stock options expired	(32,175)	(36,832)
Stock options outstanding, Ending balance	641,232	854,259
Exercisable at end of period	502,260	494,884
Expected to vest at end of period	138,972	359,375
Weighted average exercise price, Beginning balance	$ 9.34	$ 10.66
Weighted average exercise price, Stock options granted	14.12	7.34
Weighted average exercise price, Stock options exercised	7.30	7.17
Weighted average exercise price, Stock options forfeited	7.83	7.67
Weighted average exercise price, Stock options expired	12.94	16.94
Weighted average exercise price, Ending balance	9.80	9.34
Weighted average exercise price, Exercisable	10.40	10.85
Weighted average exercise price, Expected to vest, net of forfeitures	7.65	7.27
Weighted average grant date fair value, Beginning balance	4.49	5.52
Weighted average grant date fair value, Stock options granted	5.83	2.94
Weighted average grant date fair value, Stock options exercised	3.12	3.03
Weighted average grant date fair value, Stock options forfeited	3.40	3.70
Weighted average grant date fair value, Stock options expired	7.44	10.35
Weighted average grant date fair value, Ending balance	4.74	4.49
Weighted average grant date fair value, Exercisable	5.21	5.59
Weighted average grant date fair value, Expected to vest, net of forfeitures	$ 3.01	$ 2.96

Equity-Based Compensation - S_4

Equity-Based Compensation - Summary of Activity for Restricted Stock Awards (Detail) - Restricted Stock [Member] - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Restricted Shares, outstanding, Beginning Balance	66,513	67,001
Number of Restricted Shares, granted	209,891	66,763
Number of Restricted Shares, vested	(87,513)	(62,251)
Number of Restricted Shares, forfeited	0	(5,000)
Number of Restricted Shares, outstanding, Ending Balance	188,891	66,513
Number of Restricted Shares, expected to vest	188,891	66,513
Weighted Average Grant Date Fair Value, Beginning Balance	$ 8.76	$ 8.30
Weighted Average Grant Date Fair Value, granted	9.58	8.98
Weighted Average Grant Date Fair Value, vested	9.08	8.65
Weighted Average Grant Date Fair Value, forfeited	0	6.75
Weighted Average Grant Date Fair Value, Ending Balance	9.52	8.76
Weighted Average Grant Date Fair Value, expected to vest	$ 9.52	$ 8.76

Concentration of Credit Risk -

Concentration of Credit Risk - Additional Information (Detail) - Five Most Significant Customers [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Revenue, Major Customer [Line Items]
Accounts receivable from significant customers	$ 1,633	$ 3,230
Customer Concentration Risk [Member] | Sales Revenue, Net [Member]
Revenue, Major Customer [Line Items]
Revenue concentration, by most significant customers	16.40%	17.40%

Other Expense - Net - Schedule

Other Expense - Net - Schedule of Other Expense - Net (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Other Income And Expenses [Abstract]
Interest income	$ (23)	$ (11)
Foreign currency losses ̶ net	571	102
Other ̶ net	83	20
Other expense - net	$ 631	$ 111

Segment and Geographic Inform_3

Segment and Geographic Information - Geographic Information for Revenue (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 59,253	$ 53,276
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	26,804	20,897
Germany [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	24,217	20,966
Japan [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 8,232	$ 11,413

Segment and Geographic Inform_4

Segment and Geographic Information - Geographic Information for Long-Lived Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 21,300	$ 38,895
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	12,176	12,519
Germany [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	3,851	21,821
Japan [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 5,273	$ 4,555

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Feb. 26, 2021	Feb. 11, 2021	Feb. 10, 2021	Feb. 28, 2021	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Feb. 09, 2021
Subsequent Event [Line Items]
Exercise of employee stock options, shares						127,854	40,432
Proceeds from at-the-market offerings of common stock, net of issuance costs						$ 39,340
Forecast [Member] | Revolving Credit Facility [Member]
Subsequent Event [Line Items]
Cash payment					$ 105
Building Note Payable [Member] | Forecast [Member]
Subsequent Event [Line Items]
Loss on extinguishment of debt					$ 14
Subsequent Event [Member]
Subsequent Event [Line Items]
Sale of common stock				1,872,574
Proceeds from at-the-market offerings of common stock, net of issuance costs				$ 95,000
Subsequent Event [Member] | Building Note Payable [Member]
Subsequent Event [Line Items]
Cash payment	$ 1,199
Notes Payable	$ 1,185
Subsequent Event [Member] | Public Offering [Member]
Subsequent Event [Line Items]
Issued and sell of common stock			1,666,667
Sale of stock, price per share			$ 54
Additional common stock shares issued			205,907
Underwriting discount and commission per share			$ 2.835
Exercise of employee stock options, shares		205,907
Subsequent Event [Member] | Equity Distribution Agreement [Member]
Subsequent Event [Line Items]
Maximum offering capacity								$ 9,269