Plug Power (PLUG) 10-Q 9 May 22 2022 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2022	May 05, 2022
Document and Entity Information:
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Mar. 31, 2022
Entity File Number	1-34392
Entity Registrant Name	Plug Power Inc
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	22-3672377
Entity Address, Address Line One	968 ALBANY SHAKER ROAD
Entity Address, City or Town	LATHAM
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	12110
City Area Code	518
Local Phone Number	782-7700
Title of 12(b) Security	Common Stock, par value $.01 per share
Trading Symbol	PLUG
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		578,101,564
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	Q1
Document Fiscal Year Focus	2022
Entity Central Index Key	0001093691
Amendment Flag	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 2,495,614	$ 2,481,269
Restricted cash	140,117	118,633
Available-for-sale securities, at fair value (amortized cost $816,976 and allowance for credit losses of $0 at March 31, 2022 and amortized cost $1,242,933 and allowance for credit losses of $0 at December 31, 2021)	799,228	1,240,265
Equity securities	147,826	147,995
Accounts receivable	57,322	92,675
Inventory	333,379	269,163
Contract assets	38,645	38,637
Prepaid expenses and other current assets	87,763	59,888
Total current assets	4,099,894	4,448,525
Restricted cash	542,851	532,292
Property, plant, and equipment, net	324,653	255,623
Right of use assets related to finance leases, net	40,068	32,494
Right of use assets related to operating leases, net	229,508	212,537
Equipment related to power purchase agreements and fuel delivered to customers, net	77,559	72,902
Contract assets	68	120
Goodwill	232,031	220,436
Intangible assets, net	212,407	158,208
Investments in non-consolidated entities and non-marketable equity securities	41,312	12,892
Other assets	3,454	4,047
Total assets	5,803,805	5,950,076
Current liabilities:
Accounts payable	78,711	92,307
Accrued expenses	64,970	79,237
Deferred revenue and other contract liabilities	92,682	116,377
Operating lease liabilities	33,540	30,822
Finance lease liabilities	5,654	4,718
Finance obligations	44,337	42,040
Current portion of long-term debt	4,155	15,252
Loss accrual for service contracts and other current liabilities	34,282	39,800
Total current liabilities	358,331	420,553
Deferred revenue and other contract liabilities	62,503	66,713
Operating lease liabilities	186,151	175,635
Finance lease liabilities	30,520	24,611
Finance obligations	215,887	211,644
Convertible senior notes, net	192,949	192,633
Long-term debt	104,990	112,794
Loss accrual for service contracts and other liabilities	176,242	139,797
Total liabilities	1,327,573	1,344,380
Stockholders' equity:
Common stock, $0.01 par value per share; 1,500,000,000 shares authorized; Issued (including shares in treasury): 595,209,356 at March 31, 2022 and 594,729,610 at December 31, 2021	5,952	5,947
Additional paid-in capital	7,116,125	7,070,710
Accumulated other comprehensive loss	(18,462)	(1,532)
Accumulated deficit	(2,553,392)	(2,396,903)
Less common stock in treasury: 17,146,337 at March 31, 2022 and 17,074,710 at December 31, 2021	(73,991)	(72,526)
Total stockholders' equity	4,476,232	4,605,696
Total liabilities and stockholders' equity	$ 5,803,805	$ 5,950,076

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Condensed Consolidated Balance Sheets
Amortized cost	$ 816,976	$ 1,242,933
Allowance for Credit Losses	$ 0	$ 0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	1,500,000,000	1,500,000,000
Common stock, shares issued	595,209,356	594,729,610
Common stock in treasury, shares	17,146,337	17,074,710

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Net revenue:
Net revenue	$ 140,804	$ 71,958
Cost of revenue:
Provision for loss contracts related to service	2,048	1,485
Total cost of revenue	176,153	84,129
Gross loss	(35,349)	(12,171)
Operating expenses:
Research and development	20,461	9,742
Selling, general and administrative	80,890	25,579
Change in fair value of contingent consideration	2,461	790
Total operating expenses	103,812	36,111
Operating loss	(139,161)	(48,282)
Interest income	2,054	68
Interest expense	(8,648)	(12,334)
Other expense, net	(1,309)	(198)
Realized loss on investments, net	(847)
Change in fair value of equity securities	(5,159)
Loss on equity method investments	(3,833)
Loss before income taxes	(156,903)	(60,746)
Income tax benefit	(414)	0
Net loss	$ (156,489)	$ (60,746)
Net loss per share:
Net loss per share, basic	$ (0.27)	$ (0.12)
Net loss per share, diluted	$ (0.27)	$ (0.12)
Weighted average number of common stock outstanding, basic	577,866,983	513,458,287
Weighted average number of common stock outstanding, diluted	577,866,983	513,458,287
Sales of fuel cell systems, related infrastructure and equipment
Net revenue:
Net revenue	$ 108,847	$ 46,772
Cost of revenue:
Cost of revenue	88,828	28,974
Services performed on fuel cell systems and related infrastructure
Net revenue:
Net revenue	8,240	6,045
Cost of revenue:
Cost of revenue	13,875	13,086
Power purchase agreements
Net revenue:
Net revenue	10,037	7,826
Cost of revenue:
Cost of revenue	31,753	18,343
Fuel delivered to customers and related equipment
Net revenue:
Net revenue	13,429	11,127
Cost of revenue:
Cost of revenue	39,272	22,143
Other
Net revenue:
Net revenue	251	188
Cost of revenue:
Cost of revenue	$ 377	$ 98

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Condensed Consolidated Statements of Comprehensive Loss
Net loss	$ (156,489)	$ (60,746)
Foreign currency translation loss	(1,850)	(1,123)
(Loss) gain in net unrealized loss on available-for-sale securities	(15,080)	92
Comprehensive loss attributable to the Company	$ (173,419)	$ (61,777)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Common Stock7.5% Convertible Senior Note	Common StockPrivate placement	Common Stock	Additional Paid-in-Capital7.5% Convertible Senior Note	Additional Paid-in-CapitalPrivate placement	Additional Paid-in-Capital	Accumulated Other Comprehensive Income (Loss)	Treasury Stock	Accumulated Deficit	7.5% Convertible Senior Note	Private placement	Total
Balance at Dec. 31, 2020			$ 4,740			$ 3,446,650	$ 2,451	$ (40,434)	$ (1,946,488)			$ 1,466,919
Balance (in shares) at Dec. 31, 2020			473,977,469					15,926,068
Increase (Decrease) in Stockholders' Equity
Net loss									(60,746)			(60,746)
Other comprehensive (loss) gain							(1,031)					(1,031)
Stock-based compensation						9,695						9,695
Stock-based compensation (in shares)			15,166
Issuance of common stock, net		$ 549	$ 322		$ 1,564,088	2,022,866					$ 1,564,637	2,023,188
Issuance of common stock, net (in shares)		54,966,188	32,200,000
Stock option exercises			$ 18			4,691						4,709
Stock option exercises (in shares)			1,758,375
Exercise of warrants			$ 163			15,282						15,445
Exercise of warrants (in shares)			16,308,978
Provision for common stock warrants						1,601						1,601
Conversion of 7.5% Convertible Senior Note	$ 30			$ 15,155						$ 15,185
Conversion of 7.5% Convertible Senior Note (in shares)	3,016,036
Repurchase of 5.5% Convertible Senior Notes, net of income tax benefit			$ 1			159						160
Repurchase of 5.5% Convertible Senior Notes, net of income tax benefit (in shares)			69,808
Balance (ASU 2020-06) at Mar. 31, 2021						(130,249)			9,550			(120,699)
Balance at Mar. 31, 2021			$ 5,823			6,949,938	1,420	$ (40,434)	(1,997,684)			4,919,063
Balance (in shares) at Mar. 31, 2021			582,312,020					15,926,068
Balance at Dec. 31, 2021			$ 5,947			7,070,710	(1,532)	$ (72,526)	(2,396,903)			$ 4,605,696
Balance (in shares) at Dec. 31, 2021			594,729,610					17,074,710				594,729,610
Increase (Decrease) in Stockholders' Equity
Net loss									(156,489)			$ (156,489)
Other comprehensive (loss) gain							(16,930)					(16,930)
Stock-based compensation			$ 2			43,384						43,386
Stock-based compensation (in shares)			226,221
Stock option exercises and issuance of common stock under restricted stock awards			$ 3			288						291
Stock option exercises and issuance of common stock under restricted stock awards (in shares)			253,525
Treasury stock acquired from employees upon exercise of stock options								$ (1,465)				(1,465)
Treasury stock acquired from employees upon exercise of stock options (in shares)								71,627
Provision for common stock warrants						1,743						1,743
Balance at Mar. 31, 2022			$ 5,952			$ 7,116,125	$ (18,462)	$ (73,991)	$ (2,553,392)			$ 4,476,232
Balance (in shares) at Mar. 31, 2022			595,209,356					17,146,337				595,209,356

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Stockholders' Equity (Parenthetical)	Mar. 31, 2022	Mar. 31, 2021	Jan. 31, 2021	Dec. 31, 2020	May 31, 2020	May 29, 2020	May 18, 2020	Sep. 30, 2019	Mar. 31, 2018
5.5% Convertible Senior Notes
Interest rate (as a percent)		5.50%	5.50%	5.50%	5.50%				5.50%
3.75% Convertible Senior Notes
Interest rate (as a percent)	3.75%	3.75%			3.75%	3.75%	3.75%
7.5% Convertible Senior Note
Interest rate (as a percent)		7.50%						7.50%

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Operating activities
Net loss	$ (156,489)	$ (60,746)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation of long-lived assets	2,842	5,514
Amortization of intangible assets	5,190	364
Stock-based compensation	43,386	9,695
Amortization of debt issuance costs and discount on convertible senior notes	661	1,092
Provision for common stock warrants	1,852	1,705
Deferred income tax expense	(414)
Benefit on service contracts	(7,297)	(361)
Fair value adjustment to contingent consideration	(2,461)	(790)
Net realized loss on investments	847
Amortization of premium on available-for-sale securities	2,290
Lease origination costs	(1,613)
Change in fair value for equity securities	5,159
Loss on equity method investments	3,833
Changes in operating assets and liabilities that provide (use) cash:
Accounts receivable	36,170	109
Inventory	(63,702)	(46,791)
Contract assets	44
Prepaid expenses and other assets	(27,107)	(4,641)
Accounts payable, accrued expenses, and other liabilities	(25,096)	(23,516)
Deferred revenue and other contract liabilities	(28,014)	1,267
Net cash used in operating activities	(209,919)	(117,099)
Investing activities
Purchases of property, plant and equipment	(78,394)	(9,879)
Purchases of equipment related to power purchase agreements and equipment related to fuel delivered to customers	(6,796)	(3,332)
Purchase of available-for-sale securities	(114,173)	(405,168)
Proceeds from sales of available-for-sale securities	469,563
Proceeds from maturities of available-for-sale securities	67,430
Purchase of equity securities	(4,990)
Net cash paid for acquisitions	(26,473)
Cash paid for non-consolidated entities and non-marketable equity securities	(32,253)
Net cash provided by (used in) investing activities	273,914	(418,379)
Financing activities
Proceeds from exercise of warrants, net of transaction costs		15,445
Payments of contingent consideration	(2,667)
Proceeds from public and private offerings, net of transaction costs		3,587,825
Payments of tax withholding on behalf of employees for net stock settlement of stock-based compensation	(1,465)
Proceeds from exercise of stock options	291	4,709
Principal payments on long-term debt	(19,246)	(14,461)
Proceeds from finance obligations	17,273	10,661
Principal repayments of finance obligations and finance leases	(12,427)	(9,806)
Net cash (used in) provided by financing activities	(18,241)	3,594,373
Effect of exchange rate changes on cash	634	(51)
Increase in cash and cash equivalents	14,345	3,036,663
Increase in restricted cash	32,043	22,181
Cash, cash equivalents, and restricted cash beginning of period	3,132,194	1,634,284	$ 1,634,284
Cash, cash equivalents, and restricted cash end of period	3,178,582	4,693,128	$ 3,132,194
Supplemental disclosure of cash flow information
Cash paid for interest, net capitalized interest of $4.3 million	5,731	2,608
Summary of non-cash activity
Recognition of right of use asset - finance leases	8,070	5,292
Recognition of right of use asset - operating leases	20,070	12,720
Net tangible assets (liabilities) acquired (assumed) in a business combination	56,929
Intangible assets acquired in a business combination	60,522
Conversion of convertible senior notes to common stock		$ 15,345
Net transfers between inventory and long-lived assets	489
Accrued purchase of fixed assets, cash to be paid in subsequent period	$ 6,707

Condensed Consolidated Statem_6

Condensed Consolidated Statements of Cash Flows (Parenthetical) $ in Millions	3 Months Ended
	Mar. 31, 2022USD ($)
Condensed Consolidated Statements of Cash Flows
Net capitalized interest	$ 4.3

Nature of Operations

Nature of Operations	3 Months Ended
	Mar. 31, 2022
Nature of Operations
Nature of Operations	1. Nature of Operations ​ Plug Power Inc. (the “Company,” “Plug,” “we” or “our”) is facilitating the paradigm shift to an increasingly electrified world by innovating cutting-edge hydrogen and fuel cell solutions. While we continue to develop commercially-viable hydrogen and fuel cell product solutions to replace lead-acid and lithium batteries in electric material handling vehicles and industrial trucks for some of the world’s largest retail-distribution and manufacturing businesses, we have expanded our offerings to support a variety of commercial operations that can be powered with green hydrogen. We also provide electrolyzers that allow customers — such as refineries, producers of chemicals, steel and fertilizer and commercial refueling stations — to generate hydrogen on-site. Additionally, we intend for our electrolyzers to be used to generate green hydrogen within Plug’s own plants that will then be sold to customers. We are focusing our efforts on industrial mobility applications, including electric forklifts and electric industrial vehicles, at multi-shift high volume manufacturing and high throughput distribution sites where we believe our products and services provide a unique combination of productivity, flexibility, and environmental benefits. Additionally, we manufacture and sell fuel cell products to replace batteries and diesel generators in stationary back-up power applications for telecommunications, transportation, and utility customers. Plug supports these markets with an ecosystem of integrated products that make, transport, handle, dispense and use hydrogen. ​

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2022
Summary of Significant Accounting Policies
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies ​ Principles of Consolidation ​ The unaudited interim condensed consolidated financial statements include the financial statements of the Company and its wholly-owned subsidiaries. Intercompany balances and transactions have been eliminated in consolidation. In addition, we include our share of the results of HyVia, AccionaPlug S.L., and HALO Hydrogen Co, Ltd., using the equity method based on our economic ownership interest and our ability to exercise significant influence over the operating and financial decisions of HyVia, AccionaPlug S.L., and HALO Hydrogen Co, Ltd. ​ Interim Financial Statements ​ The accompanying unaudited interim condensed consolidated financial statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). In the opinion of management, all adjustments, which consist solely of normal recurring adjustments, necessary to present fairly, in accordance with U.S. generally accepted accounting principles (“GAAP”), the financial position, results of operations and cash flows for all periods presented, have been made. The results of operations for the interim periods presented are not necessarily indicative of the results that may be expected for the full year. ​ Certain information and footnote disclosures normally included in annual consolidated financial statements prepared in accordance with GAAP have been condensed or omitted. These unaudited interim condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2021 (the “2021 Form 10-K”). ​ The information presented in the accompanying unaudited interim condensed consolidated balance sheets as of December 31, 2021 has been derived from the Company’s December 31, 2021 audited consolidated financial statements. ​ The unaudited condensed consolidated financial statements contained herein should be read in conjunction with our 2021 Form 10-K . ​ ​ Recent Accounting Pronouncements Recently Adopted Accounting Guidance ​ Other than the adoption of the accounting guidance mentioned i n our 2021 Form 10-K, ​ Recent Accounting Guidance Not Yet Effective ​ All issued but not yet effective accounting and reporting standards as of March 31, 2022 are either not applicable to the Company or are not expected to have a material impact on the Company. ​ ​

Acquisitions

Acquisitions	3 Months Ended
	Mar. 31, 2022
Acquisitions
Acquisitions	3. Acquisitions ​ Joule Processing LLC ​ On January 14, 2022, the Company acquired Joule Processing LLC (“Joule”), an engineered modular equipment, process design and procurement company founded in 2009. ​ The fair value of consideration paid by the Company in connection with the Joule acquisition was as follows (in thousands): ​ ​ ​ ​ Cash $ 28,140 Contingent consideration ​ 41,732 Total consideration $ 69,872 ​ ​ The contingent consideration represents the estimated fair value associated with earn-out payments of up to $130 million that the sellers are eligible to receive in cash or shares of the Company’s common stock (at the Company’s election). Of the total earnout consideration, $90 million is related to the achievement of certain financial performance and $40 million is related to the achievement of certain internal operational milestones. ​ The following table summarizes the preliminary allocation of the purchase price to the estimated fair value of the net assets acquired, excluding goodwill (in thousands): ​ ​ ​ ​ Current assets $ 2,672 Property, plant and equipment ​ 493 Right of use asset ​ 182 Identifiable intangible assets ​ 60,522 Lease liability ​ (374) Current liabilities ​ (2,748) Contract liability ​ (3,818) Total net assets acquired, excluding goodwill $ 56,929 ​ The preliminary allocation of the purchase price is still considered provisional due to the finalization of the valuation for the assets acquired and liabilities assumed in relation to the Joule acquisition. Therefore, the fair values of the assets acquired and liabilities assumed are subject to change as we obtain additional information for valuation assumptions such as market demand for Joule product lines to support forecasted revenue growth and the likelihood of achieving earnout milestones during the measurement period, which will not exceed 12 months from the date of acquisition. ​ The fair value of the developed technology totaling $59.2 million included in the identifiable intangible assets was calculated using the multi-period excess earnings method (“MPEEM”) approach which is a variant of the income approach. The basic principle of the MPEEM approach is that a single asset, in isolation, is not capable of generating cash flow for an enterprise. Several assets are brought together and exploited to generate cash flow. Therefore, to determine cash flow from the developed technology over its useful life of 15 years , one must deduct the related expenses incurred for the exploitation of other assets used for the generation of overall cash flow. The fair value of the tradename totaling $0.8 million was calculated using the relief from royalty approach which is a variant of the income approach, and was assigned a useful life of four years . The fair value of the non-compete agreements was $0.5 million with a useful life of six years . ​ In addition to identifiable intangible assets, the fair value of acquired work in process and finished goods inventory, included in inventory, was estimated based on the estimated selling price less costs to be incurred and a market participant profit rate. ​ In connection with the acquisition, the Company recorded on its consolidated balance sheet a liability of $41.7 million representing the fair value of contingent consideration payable, and is recorded in the unaudited condensed consolidated balance sheet in the . The fair value of this contingent ​ Included in the purchase price consideration are contingent earn-out payments as described above. Due to the nature of the earn-outs, a scenario based analysis using the probability of achieving the milestone expectations was used to determine the fair value of the contingent consideration. These fair value measurements were based on unobservable inputs and are considered to be level 3 financial instruments. ​ The goodwill was primarily attributed to the value of synergies created with the Company’s current and future offerings and the value of the assembled workforce. Goodwill and intangible assets are not deductible for income tax purposes. Goodwill associated with the Joule acquisition was calculated as follows (in thousands): ​ ​ ​ ​ Consideration paid $ 28,140 Contingent consideration ​ 41,732 Less: net assets acquired ​ (56,929) Total goodwill recognized $ 12,943 ​ The acquisition of Joule contributed $1.4 million to total consolidated revenue for the three months ended March 31, 2022. Joule results are monitored by the Company and as a result, the Company determined it impractical to report net loss for the Joule acquisition for the three months ended March 31, 2022. ​ Applied Cryo Technologies Acquisition ​ On November 22, 2021, the Company acquired 100% of the outstanding shares of Applied Cryo Technologies, Inc. (“Applied Cryo”). Applied Cryo is a manufacturer of engineered equipment servicing multiple applications, including cryogenic trailers and mobile storage equipment for the oil and gas markets and equipment for the distribution of liquified hydrogen, oxygen, argon, nitrogen and other cryogenic gases. ​ The fair value of consideration paid by the Company in connection with the Applied Cryo acquisition was as follows (in thousands): ​ ​ ​ ​ Cash $ 98,559 Plug Power Inc. Common Stock ​ 46,697 Contingent consideration ​ 14,000 Settlement of preexisting relationship ​ 2,837 Total consideration $ 162,093 ​ Included in the $98.6 million of cash consideration above, $5.0 million is consideration held by our paying agent in connection with the acquisition and is reported as restricted cash, with a corresponding accrued liability as of March 31, 2022 on the Company’s unaudited interim condensed consolidated balance sheet. We expect that this will be settled in 2022. ​ The contingent consideration represents the estimated fair value associated with earn-out payments of up to $30.0 million that the sellers are eligible to receive in cash or shares of the Company’s common stock (at the Company’s election). Of the total earnout consideration, $15.0 million is related to financial performance, and $15.0 million is related to internal operational milestones. ​ The following table summarizes the preliminary allocation of the purchase price to the estimated fair value of the net assets acquired, excluding goodwill (in thousands): ​ ​ ​ ​ Cash $ 1,180 Accounts receivable ​ 4,123 Inventory 24,655 Prepaid expenses and other assets ​ 1,506 Property, plant and equipment ​ 4,515 Right of use asset ​ 2,788 Identifiable intangible assets ​ 70,484 Lease liability ​ (2,672) Accounts payable, accrued expenses and other liabilities ​ (8,206) Deferred tax liability ​ (16,541) Deferred revenue ​ (12,990) Total net assets acquired, excluding goodwill $ 68,842 ​ The preliminary allocation of the purchase price is still considered provisional due to the tradename, technology, and customer relationship valuations. The Company continues to evaluate valuation assumptions such as the market demand for the Applied Cryo existing product lines to support forecasted revenue growth. Additionally, the Company continues to research the technology and buying power of Applied Cryo and evaluate the likelihood of achieving the additional production capacity needed in a timely manner to meet earnout milestones. Any necessary adjustments will be finalized within one year from the date of acquisition. ​ Identifiable intangible assets consisted of developed technology, tradename, acquired customer relationships, non-compete agreements and backlog. The fair value of the developed technology totaling $26.3 million was calculated using the relief from royalty approach which is a variant of the income approach. The application of the relief from royalty approach involves estimating the value of an intangible asset by quantifying the present value of the stream of market derived royalty payments that the owner of the intangible asset is exempted or ‘relieved’ from paying. The developed technology has a useful life of 15 years . The fair value of the tradename totaling $13.7 million was calculated using the relief from royalty approach with a useful life of 15 years . The fair value of the acquired customer relationships totaling $26.6 million was calculated using the MPEEM approach and has a 15 year useful life. The fair value of the acquired customer relationships was estimated by discounting the net cash flow derived from the expected revenues attributable to the acquired customer relationships. The fair value of the non-compete agreements was $1.0 million with a useful life of three years . The fair value of the customer backlog was $2.9 million with a useful life of one year . ​ In addition to identifiable intangible assets, the fair value of acquired work in process and finished goods inventory, included in inventory, was estimated based on the estimated selling price less costs to be incurred and a market participant profit rate. ​ Included in the purchase price consideration are contingent earn-out payments described above. Due to the nature of the earn-outs, a scenario based analysis using the probability of achieving the milestone expectations was used to value these contingent payments. These fair value measurements were based on unobservable inputs and are considered to be level 3 financial instruments. ​ In connection with the acquisition, the Company recorded on its consolidated balance sheet a liability of $14.0 million representing the fair value of contingent consideration payable. The fair value of this contingent M arch 31, 2022, and was $14.1 million for the three months ended March 31, 2022, and $0.1 million was recorded in the unaudited condensed consolidated statement of operations for the three months ended March 31, 2022. ​ Included in Applied Cryo’s total net assets acquired, excluding goodwill, were net deferred tax liabilities of $16.5 million. In connection with the acquisition of these net deferred tax liabilities, the Company reduced its valuation allowance by $16.5 million and recognized a tax benefit $16.5 million during the year ended December 31, 2021. ​ The goodwill was primarily attributed to the value of synergies created with the Company’s current and future offerings and the value of the assembled workforce. Goodwill and intangible assets are not deductible for income tax purposes. Goodwill associated with the Applied Cryo acquisition was calculated as follows (in thousands): ​ ​ ​ ​ Consideration paid $ 162,093 Less: net assets acquired ​ (68,842) Total goodwill recognized $ 93,251 ​ The acquisition of Applied Cryo contributed $16.9 million to total consolidated revenue for the three months ended March 31, 2022. Applied Cryo results are monitored by the Company and as a result, the Company determined it impractical to report net loss for the Applied Cryo acquisition for the three months ended March 31, 2022. ​ Frames Holding B.V. Acquisition ​ On December 9, 2021, the Company acquired 100% of the outstanding shares of Frames Holding B.V. (“Frames”). Frames, a leading provider of turnkey hydrogen solutions. ​ The fair value of consideration paid by the Company in connection with the Frames acquisition was as follows (in thousands): ​ ​ ​ ​ Cash $ 94,541 Contingent consideration ​ 29,057 Settlement of preexisting relationship ​ 4,263 Total consideration $ 127,861 ​ The contingent consideration represents the estimated fair value associated with earn-out payments of up to €30.0 million that the sellers are eligible to receive in the form of cash. The contingent consideration is related to the achievement of certain internal operational targets during the four years following the closing date and is payable in two equal installments. ​ The following table summarizes the preliminary allocation of the purchase price to the estimated fair value of the total net assets acquired, excluding goodwill (in thousands): ​ ​ ​ ​ Cash $ 45,394 Accounts receivable ​ 17,910 Inventory 34 Prepaid expenses and other assets ​ 3,652 Property, plant and equipment ​ 709 Right of use asset ​ 1,937 Contract asset ​ 9,960 Identifiable intangible assets ​ 50,478 Lease liability ​ (1,937) Contract liability ​ (22,737) Accounts payable, accrued expenses and other liabilities ​ (18,465) Deferred tax liability ​ (4,105) Provision for loss contracts ​ (2,636) Warranty provisions ​ (7,566) Total net assets acquired, excluding goodwill $ 72,628 ​ The preliminary allocation of the purchase price is still considered provisional due to outstanding customer valuation analysis. Identifiable intangible assets consisted of developed technology, tradename, acquired customer relationships, non-compete agreements and backlog. ​ The fair value of the developed technology totaling $5.3 million was calculated using the relief from royalty approach which is a variant of the income approach, and it has a useful life of eight years . The fair value of the tradename totaling $11.6 million was calculated using the relief from royalty approach, and it has a useful life of eight years . The fair value of the acquired customer relationships totaling $27.2 million was calculated using the MPEEM approach which is a variant of the income approach, and it has a useful life of 17 years . The fair value of the customer relationships was estimated by discounting the net cash flow derived from the expected revenues attributable to the acquired customer relationships. The fair value of the non-compete agreements totaling $4.9 million was calculated using the with and without income approach, and it has a useful life of approximately four years . The fair value of the backlog was $1.4 million, and it has a useful life of one year . ​ Included in the purchase price consideration are contingent earn-out payments described above. Due to the nature of the earn-outs, a scenario based analysis using the probability of achieving the milestone expectations was used to determine the fair value of the contingent consideration. These fair value measurements were based on unobservable inputs and are considered to be level 3 financial instruments. ​ In connection with the acquisition, the Company recorded on its consolidated balance sheet a liability of $29.1 million representing the fair value of contingent consideration payable. The fair value of this contingent consideration was remeasured as of March 31, 2022, and was $29.4 million for the three months ended March 31, 2022. The Company recorded an adjustment of $0.3 million for the three months ended March 31, 2022 in the unaudited interim condensed consolidated statement of operations. ​ Included in Frames’ total net assets acquired, excluding goodwill, are net deferred tax liabilities of $4.1 million. ​ The goodwill was primarily attributed to the value of synergies created with the Company’s current and future offerings and the value of the assembled workforce. Goodwill and intangible assets are not deductible for income tax purposes. Goodwill associated with the Frames acquisition was calculated as follows (in thousands): ​ ​ ​ ​ Consideration paid $ 127,861 Less: net assets acquired ​ (72,628) Total goodwill recognized $ 55,233 ​ The above estimates are preliminary in nature and subject to adjustments. Any necessary adjustments will be finalized within one year from the date of acquisition. Substantially all the receivables acquired are expected to be collectable. Purchased goodwill is not expected to be deductible for tax purposes. ​ The acquisition of Frames contributed $22.0 million to total consolidated revenue for the three months ended March 31, 2022. Frames results are monitored by the Company and as a result, the Company determined it impractical to report net loss for the Frames acquisition for the three months ended March 31, 2022. ​ None of the Joule, Applied Cryo Technologies, or the Frames acquisition was material to our consolidated results of operations or financial position and, therefore, pro forma financial information is not presented.

Extended Maintenance Contracts

Extended Maintenance Contracts	3 Months Ended
	Mar. 31, 2022
Extended Maintenance Contracts
Extended Maintenance Contracts	4. Extended Maintenance Contracts ​ On a quarterly basis, we evaluate any potential losses related to our extended maintenance contracts for fuel cell systems and related infrastructure that have been sold. The following table shows the rollforward of balance in the accrual for loss contracts, including changes due to the provision for loss accrual, loss accrual from acquisition, releases to service cost of sales, and releases due to the provision for warrants (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ Year ended ​ March 31, 2022 ​ December 31, 2021 Beginning balance $ 89,773 ​ $ 24,013 Provision for loss accrual ​ 2,048 ​ ​ 71,988 Loss accrual from acquisition ​ — ​ ​ 2,636 Releases to service cost of sales ​ (9,345) ​ ​ (8,864) Ending balance $ 82,476 ​ $ 89,773 ​

Earnings Per Share

Earnings Per Share	3 Months Ended
	Mar. 31, 2022
Earnings Per Share
Earnings Per Share	5. Earnings Per Share ​ Basic earnings per common stock are computed by dividing net loss attributable to common stockholders by the weighted average number of common stock outstanding during the reporting period. In periods when we have net income, the shares of our common stock subject to the convertible notes outstanding during the period will be included in our diluted earnings per share under the if-converted method. Since the Company is in a net loss position, all common stock equivalents would be considered anti-dilutive and are therefore not included in the determination of diluted earnings per share. Accordingly, basic and diluted loss per share are the same. ​ The potentially dilutive securities are summarized as follows: ​ ​ ​ ​ ​ ​ ​ ​ At March 31, ​ 2022 2021 Stock options outstanding (1) ​ 24,185,000 9,020,891 Restricted stock outstanding (2) ​ 5,439,207 6,416,308 Common stock warrants (3) ​ 80,017,181 ​ 88,264,726 Convertible Senior Notes (4) ​ 39,170,766 39,170,766 Number of dilutive potential shares of common stock ​ 148,812,154 142,872,691 ​ (1) During the three months ended March 31, 2022 and 2021, the Company granted options for 451,500 and 581,000 shares of common stock, respectively. ​ (2) During the three months ended March 31, 2022 and 2021, the Company granted 802,500 and 555,000 restricted shares of common stock, respectively. ​ (3) In April 2017, the Company issued a warrant to acquire up to 55,286,696 shares of the Company’s common stock as part of a transaction agreement with Amazon, subject to certain vesting events, as described in Note 12, “Warrant Transaction Agreements.” The warrant had been exercised with respect to 17,461,994 and 9,214,449 shares of the Company’s common stock as of March 31, 2022 and 2021, respectively. ​ In July 2017, the Company issued a warrant to acquire up to 55,286,696 shares of the Company’s common stock as part of a transaction agreement with Walmart, subject to certain vesting events, as described in Note 12, “Warrant Transaction Agreements.” The warrant had been exercised with respect to 13,094,217 shares of the Company’s common stock as of March 31, 2022 and 2021. ​ (4) In March 2018, the Company issued $100.0 million in aggregate principal amount of the 5.5% Convertible Senior Notes due 2023 (the “5.5% Convertible Senior Notes”). In May 2020, the Company repurchased $66.3 million of the 5.5% Convertible Senior Notes and in the fourth quarter of 2020, $33.5 million of the 5.5% Convertible Senior Notes were converted into approximately 14.6 million shares of common stock. The remaining $160.0 thousand aggregate principal amount of the 5.5% Convertible Senior Notes were converted into 69,808 shares of common stock in January 2021. In September 2019, the Company issued $40.0 million in aggregate principal amount of the 7.5% Convertible Senior Note due 2023 (the “7.5% Convertible Senior Note”), which was fully converted into 16.0 million shares of common stock on July 1, 2020. In May 2020, the Company issued $212.5 million in aggregate principal amount of the 3.75% Convertible Senior Notes. There were no conversions for the three months ended March 31, 2022. For the three months ended March 31, 2021, $15.2 million of the 3.75% Convertible Senior Notes were converted, resulting in the issuance of 3,016,036 shares of common stock.

Inventory

Inventory	3 Months Ended
	Mar. 31, 2022
Inventory
Inventory	​ 6. Inventory ​ Inventory as of March 31, 2022 and December 31, 2021 consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, December 31, ​ ​ 2022 ​ 2021 ​ Raw materials and supplies - production locations ​ $ 247,100 ​ $ 187,449 ​ Raw materials and supplies - customer locations ​ ​ 14,301 ​ ​ 16,294 ​ Work-in-process ​ 62,558 ​ 58,341 ​ Finished goods ​ 9,420 ​ 7,079 ​ Inventory ​ $ 333,379 ​ $ 269,163 ​ ​

Property, Plant and Equipment

Property, Plant and Equipment	3 Months Ended
	Mar. 31, 2022
Property, Plant and Equipment
Property, Plant and Equipment	7. Property, Plant and Equipment ​ Property, plant and equipment at March 31, 2022 and December 31, 2021 consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2022 ​ December 31, 2021 Land ​ $ 1,165 ​ $ 1,165 Construction in progress ​ ​ 235,548 ​ ​ 169,415 Leasehold improvements ​ ​ 2,645 ​ ​ 2,099 Software, machinery, and equipment ​ 116,974 ​ 112,068 Property, plant, and equipment ​ 356,332 ​ 284,747 Less: accumulated depreciation ​ (31,679) ​ (29,124) Property, plant, and equipment, net ​ $ 324,653 ​ $ 255,623 ​ Construction in progress is primarily comprised of construction of hydrogen production plants and the Gigafactory in Rochester, NY. Completed assets are transferred to their respective asset classes, and depreciation begins when an asset is ready for its intended use. Interest on outstanding debt is capitalized during periods of capital asset construction and amortized over the useful lives of the related assets. During the three months ended March 31, 2022 and 2021, we capitalized $4.3 million and $0 of interest, respectively. ​ Depreciation expense related to property, plant and equipment was $2.6 million and $1.6 million for the three months ended March 31, 2022 and 2021, respectively.

Intangible Assets and Goodwill

Intangible Assets and Goodwill	3 Months Ended
	Mar. 31, 2022
Intangible Assets and Goodwill
Intangible Assets and Goodwill	8. Intangible Assets and Goodwill ​ The gross carrying amount and accumulated amortization of the Company’s acquired identifiable intangible assets as of March 31, 2022 were as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted Average ​ Gross Carrying ​ Accumulated ​ ​ ​ ​ ​ ​ Amortization Period ​ Amount ​ Amortization ​ Total Acquired technology 14 years $ 104,605 ​ $ (7,121) ​ $ 97,484 ​ Dry stack electrolyzer technology ​ 5 years ​ ​ 29,000 ​ ​ (483) ​ ​ 28,517 ​ Customer relationships, Non-compete agreements, Backlog & Trademark ​ 12 years ​ 90,811 ​ ​ (4,405) ​ ​ 86,406 ​ ​ ​ ​ ​ $ 224,416 ​ $ (12,009) ​ $ 212,407 ​ ​ The gross carrying amount and accumulated amortization of the Company’s acquired identifiable intangible assets as of December 31, 2021 were as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted Average ​ Gross Carrying ​ Accumulated ​ ​ ​ ​ ​ ​ Amortization Period ​ Amount ​ Amortization ​ Total Acquired technology 13 years ​ $ 45,530 ​ $ (5,392) ​ $ 40,138 ​ Customer relationships, Non-compete agreements, Backlog & Trademark ​ 12 years ​ ​ 90,497 ​ ​ (1,427) ​ ​ 89,070 ​ In process research and development Indefinite ​ 29,000 ​ ​ — ​ 29,000 ​ ​ ​ ​ ​ $ 165,027 ​ $ (6,819) ​ $ 158,208 ​ ​ The change in the gross carrying amount of the acquired technology from December 31, 2021 to March 31, 2022 was primarily due to the acquisition of Joule, the addition of the dry build electrolyzer stack related to the Giner ELX acquisition, and changes in foreign currency translation. ​ Amortization expense for acquired identifiable intangible assets for the three months ended March 31, 2022 and 2021 was $5.2 million and $0.4 million, respectively. ​ The estimated amortization expense for subsequent years is as follows (in thousands): ​ ​ ​ ​ ​ Remainder of 2022 $ 18,743 2023 ​ ​ 21,189 2024 ​ ​ 21,131 2025 ​ ​ 20,353 2026 ​ ​ 18,797 2027 and thereafter ​ ​ 112,194 Total ​ $ 212,407 ​ The change in the carrying amount of goodwill for the three month period ended March 31, 2022 was as follows (in thousands): ​ ​ ​ ​ ​ Beginning balance at December 31, 2021 ​ $ 220,436 Acquisitions ​ ​ 12,943 Adjustments ​ ​ (52) Loss due to currency translation ​ (1,296) Ending balance at March 31, 2022 ​ $ 232,031

Long-Term Debt

Long-Term Debt	3 Months Ended
	Mar. 31, 2022
Long-Term Debt
Long-Term Debt	9. Long-Term Debt ​ In March 2019, the Company entered into a loan and security agreement, as amended (the “Loan Agreement”), with Generate Lending, LLC (“Generate Capital”), providing for a secured term loan facility in the amount of $100 million (the “Term Loan Facility”). On March 31, 2022, the outstanding balance under the Term Loan Facility was $99.8 million. The carrying value of the Term Loan Facility approximates fair value. ​ The Loan Agreement includes covenants, limitations, and events of default customary for similar facilities. Interest and a portion of the principal amount is payable on a quarterly basis. Principal payments are funded in part by releases of restricted cash, as described in Note 19, “Commitments and Contingencies.” Based on the amortization schedule as of March 31, 2022, the aforementioned loan balance under the Term Loan Facility will be fully paid by October 31, 2025. At March 31, 2022, the Company was in compliance with all debt covenants under the Term Loan Facility. ​ ​

Convertible Senior Notes

Convertible Senior Notes	3 Months Ended
	Mar. 31, 2022
Convertible Senior Notes.
Convertible Senior Notes	10. Convertible Senior Notes ​ 3.75% Convertible Senior Notes ​ On May 18, 2020, the Company issued $200.0 million in aggregate principal amount of 3.75% Convertible Senior Notes due June 1, 2025, in a private placement to qualified institutional buyers pursuant to Rule 144A under the Securities Act of 1933, as amended (the “Securities Act”). On May 29, 2020, the Company issued an additional $12.5 million in aggregate principal amount of 3.75% Convertible Senior Notes. During the three months ended March 31, 2022, there were no conversions of the 3.75% Convertible Senior Notes. The 3.75% Convertible Senior Notes consisted of the following (in thousands): ​ ​ ​ ​ ​ March 31, ​ 2022 Principal amounts: ​ ​ Principal $ 197,278 Unamortized debt issuance costs (1) ​ (4,329) Net carrying amount $ 192,949 1) Included in the unaudited interim condensed consolidated balance sheets within the 3.75% Convertible Senior Notes, net and amortized over the remaining life of the notes using the effective interest rate method. ​ The following table summarizes the total interest expense and effective interest rate related to the 3.75% Convertible Senior Notes (in thousands, except for effective interest rate): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ ​ March 31, ​ ​ 2022 ​ 2021 ​ Interest expense ​ $ 1,849 ​ $ 1,897 ​ Amortization of debt issuance costs ​ ​ 316 ​ ​ 1,258 ​ Total ​ ​ 2,165 ​ ​ 3,155 ​ ​ ​ ​ ​ ​ ​ ​ ​ Effective interest rate ​ ​ 4.5% ​ ​ 4.5% ​ ​ ​ Capped Call ​ In conjunction with the pricing of the 3.75% Convertible Senior Notes, the Company entered into privately negotiated capped call transactions (the “3.75% Notes Capped Call”) with certain counterparties at a price of $16.2 million. The 3.75% Notes Capped Call covers, subject to anti-dilution adjustments, the aggregate number of shares of the Company’s common stock that underlie the initial 3.75% Convertible Senior Notes and The net cost incurred in connection with the 3.75% Notes Capped Call were recorded as a reduction to additional paid-in capital in the unaudited interim condensed consolidated balance sheets. ​ The book value of the 3.75% Notes Capped Call is not remeasured. ​ Common Stock Forward ​ In March 2018, the Company issued $100.0 million in aggregate principal amount of the 5.5% Convertible Senior Notes due on March 15, 2023, in a private placement to qualified institutional buyers pursuant to Rule 144A under the Securities Act, which have been fully converted into shares of common stock. In connection with the issuance of the 5.5% Convertible Senior Notes, the Company entered into a forward stock purchase transaction (the “Common Stock Forward”), pursuant to which the Company agreed to purchase 14,397,906 shares of its common stock for settlement on or about March 15, 2023. On May 18, 2020, the Company amended and extended the maturity of the Common Stock Forward to June 1, 2025. The number of shares of common stock that the Company will ultimately repurchase under the Common Stock Forward is subject to customary anti-dilution adjustments. The Common Stock Forward is subject to early settlement or settlement with alternative consideration in the event of certain corporate transactions. ​ The net cost incurred in connection with the Common Stock Forward of $27.5 million was recorded as an increase in treasury stock in the unaudited interim condensed consolidated balance sheets. The related shares were accounted for as a repurchase of common stock. ​ The book value of the Common Stock Forward is not remeasured. ​ There were no shares of common stock settled in connection with the Common Stock Forward during the three months ended March 31, 2022. During the three months ended March 31, 2021, the Common Stock Forward was partially settled and 5.9 million shares were received by the Company.

Stockholders' Equity

Stockholders' Equity	3 Months Ended
	Mar. 31, 2022
Stockholders' Equity
Stockholders' Equity	11. Stockholders’ Equity ​ Common Stock and Warrants ​ In February 2021, the Company completed a sale of its common stock in connection with a strategic partnership with SK Holdings Co., Ltd. (“SK Holdings”) to accelerate the use of hydrogen as an alternative energy source in Asian markets. The Company sold 54,966,188 shares of its common stock to a subsidiary of SK Holdings at a purchase price of $29.2893 per share, or an aggregate purchase price of approximately $1.6 billion. ​ In January and February 2021, the Company issued and sold in a registered equity offering an aggregate of 32.2 million shares of its common stock at a purchase price of $65.00 per share for net proceeds of approximately $2.0 billion. ​ In November 2020, the Company issued and sold in a registered equity offering an aggregate of 43,700,000 shares of its common stock at a purchase price of $22.25 per share for net proceeds of approximately $927.3 million. ​ In August 2020, the Company issued and sold in a registered equity offering an aggregate of 35,276,250 shares of its common stock at a purchase price of $10.25 per share for net proceeds of approximately $344.4 million. ​ During 2017, warrants to purchase up to 110,573,392 shares of common stock were issued in connection with transaction agreements with Amazon and Walmart, as discussed in Note 12, “Warrant Transaction Agreements.” At March 31, 2022 and December 31, 2021, 75,655,478 of the warrant shares had vested, and were therefore exercisable. These warrants are measured at fair value at the time of grant or modification and are classified as equity instruments on the unaudited interim condensed consolidated balance sheets.

Warrant Transaction Agreements

Warrant Transaction Agreements	3 Months Ended
	Mar. 31, 2022
Warrant Transaction Agreements
Warrant Transaction Agreements	12. Warrant Transaction Agreements ​ Amazon Transaction Agreement ​ On April 4, 2017, the Company and Amazon entered into a Transaction Agreement (the “Amazon Transaction Agreement”), pursuant to which the Company agreed to issue to Amazon.com NV Investment Holdings LLC, a wholly owned subsidiary of Amazon, a warrant (the “Amazon Warrant”) to acquire up to 55,286,696 shares of the Company’s common stock (the “Amazon Warrant Shares”), subject to certain vesting events described below. The Company and Amazon entered into the Amazon Transaction Agreement in connection with existing commercial agreements between the Company and Amazon with respect to the deployment of the Company’s GenKey fuel cell technology at Amazon distribution centers. The existing commercial agreements contemplate, but do not guarantee, future purchase orders for the Company’s fuel cell technology. The vesting of the Amazon Warrant Shares was conditioned upon payments made by Amazon or its affiliates (directly or indirectly through third parties) pursuant to the existing commercial agreements. ​ The warrant had been exercised with respect to 17,461,994 shares of the Company’s common stock as of both March 31, 2022 and December 31, 2021. ​ At December 31, 2021, all 55,286,696 of the Amazon Warrant Shares had vested. For service contracts entered into prior to December 31, 2020, the warrant charge associated with that revenue was capitalized and is subsequently amortized over the life of the service contract. The total amount of provision for common stock warrants recorded as a reduction of revenue for the Amazon Warrant during the three months ended March 31, 2022 and 2021 was $110 thousand and $104 thousand, respectively. ​ Walmart Transaction Agreement ​ On July 20, 2017, the Company and Walmart entered into a Transaction Agreement (the “Walmart Transaction Agreement”), pursuant to which the Company agreed to issue to Walmart a warrant (the “Walmart Warrant”) to acquire up to 55,286,696 shares of the Company’s common stock, subject to certain vesting events (the “Walmart Warrant Shares”). The Company and Walmart entered into the Walmart Transaction Agreement in connection with existing commercial agreements between the Company and Walmart with respect to the deployment of the Company’s GenKey fuel cell technology across various Walmart distribution centers. The existing commercial agreements contemplate, but do not guarantee, future purchase orders for the Company’s fuel cell technology. The vesting of the warrant shares conditioned upon payments made by Walmart or its affiliates (directly or indirectly through third parties) pursuant to transactions entered into after January 1, 2017 under existing commercial agreements. ​ The warrant had been exercised with respect to 13,094,217 shares of the Company’s common stock as of both March 31, 2022 and December 31, 2021. ​ At both March 31, 2022 and December 31, 2021, 20,368,782 of the Walmart Warrant Shares had vested. The total amount of provision for common stock warrants recorded as a reduction of revenue for the Walmart Warrant during the three months ended March 31, 2022 and 2021 was $1.7 million and $1.6 million, respectively. During the three months ended March 31, 2022 and 2021, respectively, the Walmart Warrant was exercised with respect to 0 and 7,274,565 shares of common stock.

Revenue

Revenue	3 Months Ended
	Mar. 31, 2022
Revenue
Revenue	13. Revenue ​ Disaggregation of revenue ​ The following table provides information about disaggregation of revenue (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ Major products/services lines ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended March 31, ​ ​ ​ 2022 ​ 2021 ​ Sales of fuel cell systems ​ $ 37,528 ​ $ 26,419 ​ Sales of hydrogen infrastructure ​ ​ 27,089 ​ ​ 20,353 ​ Sales of electolyzers ​ ​ 4,059 ​ ​ — ​ Sales of oil and gas equipment ​ ​ 21,968 ​ ​ — ​ Services performed on fuel cell systems and related infrastructure ​ ​ 8,240 ​ ​ 6,045 ​ Power Purchase Agreements ​ ​ 10,037 ​ ​ 7,826 ​ Fuel delivered to customers ​ ​ 13,429 ​ ​ 11,127 ​ Sales of cryogenic equipment ​ ​ 18,203 ​ ​ — ​ Other ​ ​ 251 ​ ​ 188 ​ Net revenue ​ $ 140,804 ​ $ 71,958 ​ ​ Contract balances ​ The following table provides information about receivables, contract assets and contract liabilities from contracts with customers (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ ​ 2022 ​ 2021 Accounts receivable ​ $ 57,322 ​ $ 92,675 Contract assets ​ ​ 38,713 ​ ​ 38,757 Contract liabilities ​ ​ 155,185 ​ ​ 183,090 ​ Contract assets relate to contracts for which revenue is recognized on a straight-line basis; however, billings escalate over the life of a contract. Contract assets also include amounts recognized as revenue in advance of billings to customers, which are dependent upon the satisfaction of another performance obligation. These amounts are included in contract assets on the accompanying unaudited interim condensed consolidated balance sheets. ​ The contract liabilities relate to the advance consideration received from customers for services that will be recognized over time (primarily fuel cell and related infrastructure services) and advance consideration received from customers prior to delivery of products. These amounts are included within deferred revenue and other contract liabilities on the unaudited interim condensed consolidated balance sheets. ​ Significant changes in the contract assets and the contract liabilities balances during the period are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Contract assets ​ Three months ended ​ ​ March 31, 2022 ​ December 31, 2021 Transferred to receivables from contract assets recognized at the beginning of the period ​ $ (3,693) ​ $ (14,638) Contract assets assumed as part of acquisition ​ ​ — ​ ​ 9,960 Revenue recognized and not billed as of the end of the period ​ ​ 3,649 ​ ​ 25,246 Net change in contract assets ​ $ (44) ​ $ 20,568 ​ ​ ​ ​ ​ ​ ​ ​ ​ Contract liabilities ​ Three months ended ​ ​ March 31, 2022 ​ December 31, 2021 Increases due to cash received, net of amounts recognized as revenue during the period ​ $ 13,327 ​ $ 182,052 Contract liabilities assumed as part of acquisitions ​ ​ 3,818 ​ ​ 35,727 Revenue recognized that was included in the contract liability balance as of the beginning of the period ​ ​ (45,050) ​ ​ (110,974) Net change in contract liabilities ​ $ (27,905) ​ $ 106,805 ​ Estimated future revenue ​ The following table includes estimated revenue included in the backlog expected to be recognized in the future (sales of fuel cell systems and hydrogen Power Purchase five ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ ​ 2022 Sales of fuel cell systems ​ $ 16,466 Sale of hydrogen installations and other infrastructure ​ ​ 40,487 Sale of electrolyzers ​ ​ 51,267 Sales of oil and gas equipment ​ ​ 73,270 Services performed on fuel cell systems and related infrastructure ​ ​ 98,635 Power Purchase Agreements ​ ​ 255,929 Fuel delivered to customers and related equipment ​ ​ 83,796 Sale of cryogenic equipment ​ ​ 62,299 Total estimated future revenue ​ $ 682,149 ​ Contract costs ​ Contract costs consist of capitalized commission fees and other expenses related to obtaining or fulfilling a contract. Capitalized contract costs at March 31, 2022 and March 31, 2021 were $0.5 million and $1.7 million, respectively.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2022
Income Taxes
Income Taxes	14. Income Taxes ​ The domestic net deferred tax asset generated from the Company’s net operating loss has been offset by a full valuation allowance because it is more likely than not that the tax benefits of the net operating loss carry forward will not be realized. The Company recognizes accrued interest and penalties related to unrecognized tax benefits, if any, as a component of income tax expense.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2022
Fair Value Measurements
Fair Value Measurements	15. Fair Value Measurements ​ The Company records the fair value of assets and liabilities in accordance with ASC 820, Fair Value Measurement ​ In addition to defining fair value, ASC 820 expands the disclosure requirements around fair value and establishes a fair value hierarchy for valuation inputs. The hierarchy prioritizes the inputs into three levels based on the extent to which inputs used in measuring fair value are observable in the market. Each fair value measurement is reported in one of the three levels, which is determined by the lowest level input that is significant to the fair value measurement in its entirety. ​ These levels are: ● Level 1 — quoted prices (unadjusted) in active markets for identical assets or liabilities. ● Level 2 — quoted prices for similar assets and liabilities in active markets or inputs that are observable for the asset or liability, either directly or indirectly through market corroboration, for substantially the full term of the financial instrument. ● Level 3 — unobservable inputs reflecting management’s own assumptions about the inputs used in pricing the asset or liability at fair value. ​ Securities reported at fair value utilizing Level 1 inputs represent assets whose fair value is determined based upon observable unadjusted quoted market prices for identical assets in active markets. Level 2 securities represent assets whose fair value is determined using observable market information such as previous day trade prices, quotes from less active markets or quoted prices of securities with similar characteristics. Available-for-sale securities are characterized as Level 2 assets, as their fair values are determined using observable market inputs. Equity securities are characterized as Level 1 assets, as their fair values are determined using active markets for identical assets. There were no transfers between Level 1 Level 2 Level 3 three ​ Financial instruments not recorded at fair value on a recurring basis include equity method investments that have not been remeasured or impaired in the current period, such as our investments in HyVia, AccionaPlug S.L., and HALO Hydrogen Co, Ltd. During the three months ended March 31, 2022, the Company contributed approximately $22.6 million to HyVia, AccionaPlug S.L. and HALO Hydrogen Co, Ltd. ​ Assets and liabilities measured at fair value on a recurring basis are summarized below (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of March 31, 2022 ​ ​ Carrying ​ Fair ​ Fair Value Measurements ​ ​ Amount ​ Value ​ Level 1 ​ Level 2 ​ Level 3 Assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash equivalents $ 37,116 $ 37,116 $ 37,116 $ — $ — Corporate bonds ​ 244,921 ​ 244,921 ​ — ​ 244,921 ​ — U.S. Treasuries ​ 554,307 ​ 554,307 ​ 554,307 ​ — ​ — Equity securities ​ 147,826 ​ 147,826 ​ 147,826 ​ — ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Contingent consideration ​ 103,219 ​ 103,219 ​ — ​ — ​ 103,219 Swaps and forward contracts ​ 371 ​ (1,165) ​ 1,165 ​ — ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2021 ​ ​ Carrying ​ Fair ​ Fair Value Measurements ​ ​ Amount ​ Value ​ Level 1 ​ Level 2 ​ Level 3 Assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash equivalents $ 115,241 $ 115,241 $ 115,241 $ — $ — Corporate bonds ​ 226,382 ​ 226,382 ​ — ​ 226,382 ​ — U.S. Treasuries ​ 1,013,883 ​ 1,013,883 ​ 1,013,883 ​ — ​ — Equity securities ​ 147,995 ​ 147,995 ​ 147,995 ​ — ​ — Swaps and forward contracts ​ 70 ​ 70 ​ 70 ​ — ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Contingent consideration ​ 62,297 ​ 62,297 ​ — ​ — ​ 62,297 Swaps and forward contracts ​ 981 ​ 981 ​ 981 ​ — ​ — ​ ​ The assets and liabilities measured at fair value on a recurring basis that have unobservable inputs and are therefore categorized as level 3 are: ​ ​ ​ ​ ​ ​ ​ ​ Financial Instrument Fair Value Valuation Technique Unobservable Input Range (weighted average) Contingent Consideration ​ $ 89,670 Scenario based method Credit spread 12.34% - 13.77% (13.06%) ​ ​ ​ ​ ​ Discount rate 13.84% - 16.06% (14.95%) ​ ​ ​ 10,400 Monte carlo simulation Credit spread 12.50% ​ ​ ​ ​ ​ Discount rate 14.63% ​ ​ ​ ​ ​ Revenue volatility 57.24% (35.0%) ​ ​ ​ 3,149 Monte carlo simulation Credit spread 13.00% - 13.08% (12.92%) ​ ​ ​ ​ ​ Revenue volatility 47.7% - 25.9% (35.0%) ​ ​ ​ ​ ​ Gross profit volatility 113.9% - 24.2% (70.0%) ​ ​ ​ 103,219 ​ ​ ​ ​ The change in the carrying amount of Level 3 liabilities for the three month period ended March 31, 2022 was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ Three months ended ​ ​ ​ March 31, 2022 Beginning balance at December 31, 2021 ​ $ 62,297 Payments ​ ​ (2,667) Additions due to acquisitions ​ ​ 41,732 Fair value adjustments ​ ​ 2,461 Gain due to currency translation ​ (604) Ending balance at March 31, 2022 ​ $ 103,219 ​

Investments

Investments	3 Months Ended
	Mar. 31, 2022
Investments
Investments	16. Investments ​ The amortized cost, gross unrealized gains and losses, fair value of those investments classified as available-for-sale, and allowance for credit losses at March 31, 2022 are summarized as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2022 ​ Amortized ​ Gross ​ Gross ​ Fair ​ Allowance for ​ Cost ​ Unrealized Gains ​ Unrealized Losses ​ Value ​ Credit Losses Corporate bonds $ 251,827 ​ $ — ​ $ (6,906) ​ $ 244,921 ​ ​ — U.S. Treasuries ​ 565,149 ​ ​ — ​ ​ (10,842) ​ ​ 554,307 ​ ​ — Total $ 816,976 ​ $ — ​ $ (17,748) ​ $ 799,228 ​ $ — ​ The amortized cost, gross unrealized gains and losses, fair value of those investments classified as available-for-sale, and allowance for credit losses at December 31, 2021 are summarized as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ Amortized ​ Gross ​ Gross ​ Fair ​ Allowance for ​ Cost ​ Unrealized Gains ​ Unrealized Losses ​ Value ​ Credit Losses Corporate bonds $ 228,614 ​ $ — ​ $ (2,232) ​ $ 226,382 ​ ​ — U.S. Treasuries ​ 1,014,319 ​ ​ 20 ​ ​ (456) ​ ​ 1,013,883 ​ ​ — Total $ 1,242,933 ​ $ 20 ​ $ (2,688) ​ $ 1,240,265 ​ $ — ​ ​ The cost, gross unrealized gains and losses, and fair value of those investments classified as equity securities at March 31, 2022 are summarized as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2022 ​ ​ ​ ​ Gross ​ Gross ​ Fair ​ ​ Cost ​ Unrealized Gains ​ Unrealized Losses ​ Value Fixed income mutual funds $ 70,247 $ — ​ $ (1,772) ​ $ 68,475 Exchange traded mutual funds ​ 76,000 ​ ​ 3,351 ​ ​ — ​ ​ 79,351 Total $ 146,247 ​ $ 3,351 ​ $ (1,772) ​ $ 147,826 ​ The cost, gross unrealized gains and losses, and fair value of those investments classified as equity securities at December 31, 2021 are summarized as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ ​ ​ ​ Gross ​ Gross ​ Fair ​ ​ Cost ​ Unrealized Gains ​ Unrealized Losses ​ Value Fixed income mutual funds $ 70,247 $ — ​ $ (574) ​ $ 69,673 Exchange traded mutual funds ​ 71,010 ​ ​ 7,312 ​ ​ — ​ ​ 78,322 Total $ 141,257 ​ $ 7,312 ​ $ (574) ​ $ 147,995 ​ A summary of the amortized cost and fair value of investments classified as available-for-sale, by contractual maturity, as of March 31, 2022 and December 31, 2021 was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2022 ​ December 31, 2021 ​ ​ Amortized ​ Fair ​ ​ Amortized ​ Fair Maturity: ​ Cost ​ Value ​ ​ Cost ​ Value Within one year $ 307,565 $ 305,681 ​ $ 670,584 $ 670,306 After one through five years 509,411 ​ 493,547 ​ 572,349 ​ 569,959 Total $ 816,976 ​ $ 799,228 ​ $ 1,242,933 ​ $ 1,240,265 ​ Accrued interest income was $3.3 million and $3.7 million at March 31, 2022 and December 31, 2021, respectively, and included within the balance for prepaid expenses and other current assets in the unaudited interim condensed consolidated balance sheets.

Operating and Finance Lease Lia

Operating and Finance Lease Liabilities	3 Months Ended
	Mar. 31, 2022
Operating and Finance Lease Liabilities
Operating and Finance Lease Liabilities	17. Operating and Finance Lease Liabilities ​ As of March 31, 2022 the Company had operating leases, as lessee, primarily associated with sale/leaseback transactions that are partially secured by restricted cash, security deposits and pledged escrows (see also Note 1, “Nature of Operations”) as summarized below. These leases expire over the next one ​ Leases contain termination clauses with associated penalties, the amount of which cause the likelihood of cancellation to be remote. At the end of the lease term, the leased assets may be returned to the lessor by the Company, the Company may negotiate with the lessor to purchase the assets at fair market value, or the Company may negotiate with the lessor to renew the lease at market rental rates. No residual value guarantees are contained in the leases. No financial covenants are contained within the lease; however, the lease contains customary operational covenants such as the requirement that the Company properly maintain the leased assets and carry appropriate insurance. The leases include credit support in the form of either cash, collateral or letters of credit. See Note 19, “Commitments and Contingencies” for a description of cash held as security associated with the leases. ​ The Company has finance leases associated with its property and equipment in Latham, New York and at fueling customer locations. The fair value of this finance obligation approximated the carrying value as of March 31, 2022. ​ Future minimum lease payments under operating and finance leases (with initial or remaining lease terms in excess of one year) as of March 31, 2022 were as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Finance ​ Total ​ ​ Operating Lease ​ Lease ​ Lease ​ ​ Liability ​ Liability ​ Liabilities Remainder of 2022 ​ $ 42,373 ​ $ 5,929 ​ $ 48,302 2023 ​ ​ 56,034 ​ 7,800 ​ ​ 63,834 2024 ​ ​ 54,667 ​ 7,773 ​ ​ 62,440 2025 ​ ​ 50,800 ​ 10,671 ​ ​ 61,471 2026 ​ ​ 43,515 ​ ​ 8,039 ​ ​ 51,554 2027 and thereafter ​ ​ 43,652 ​ ​ 2,343 ​ ​ 45,995 Total future minimum payments ​ ​ 291,041 ​ 42,555 ​ ​ 333,596 Less imputed interest ​ ​ (71,350) ​ ​ (6,381) ​ ​ (77,731) Total ​ $ 219,691 ​ $ 36,174 ​ $ 255,865 ​ Rental expense for all operating leases was $14.0 million and $8.0 million for the three months ended March 31, 2022 and 2021, respectively. ​ At March 31, 2022 and December 31, 2021, security deposits associated with sale/leaseback transactions were $3.8 million and $3.5 million, respectively, and were included in other assets in the unaudited interim condensed consolidated balance sheets. ​ At March 31, 2022 and December 31, 2021, the right of use assets associated with finance leases was $42.3 million and $33.9 million, respectively. The accumulated depreciation for these right of use assets was $2.2 million and $1.5 million at March 31, 2022 and December 31, 2021, respectively. ​ Other information related to the operating leases are presented in the following table: ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ Three months ended ​ March 31, 2022 ​ March 31, 2021 Cash payments (in thousands) $ 13,547 ​ $ 6,734 Weighted average remaining lease term (years) ​ 5.46 ​ ​ 5.77 Weighted average discount rate ​ 10.9% ​ ​ 11.6% ​ Finance lease costs include amortization of the right of use assets (i.e., depreciation expense) and interest on lease liabilities (i.e., interest and other expense, net in the consolidated statement of operations), and were $749 thousand and $556 thousand for the three months ended March 31, 2022, respectively. ​ Other information related to the finance leases are presented in the following table: ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ Three months ended ​ March 31, 2022 ​ March 31, 2021 Cash payments (in thousands) $ 1,868 ​ $ 433 Weighted average remaining lease term (years) ​ 4.44 ​ ​ 5.10 Weighted average discount rate ​ 6.5% ​ ​ 7.2% ​

Finance Obligation

Finance Obligation	3 Months Ended
	Mar. 31, 2022
Finance Obligation
Finance Obligation	18. Finance Obligation ​ The Company has sold future services to be performed associated with certain sale/leaseback transactions and recorded the balance as a finance obligation. The outstanding balance of this obligation at March 31, 2022 was $244.1 million, $40.5 million and $203.6 million of which was classified as short-term and long-term, respectively, on the accompanying unaudited interim condensed consolidated balance sheet. The outstanding balance of this obligation at December 31, 2021 was $236.6 million, $37.5 million and $199.1 million of which was classified as short-term and long-term, respectively. The amount is amortized using the effective interest method. The fair value of this finance obligation approximated the carrying value as of March 31, 2022 and December 31, 2021. ​ In prior periods, the Company entered into sale/leaseback transactions that were accounted for as financing transactions and reported as part of finance obligations. The outstanding balance of finance obligations related to sale/leaseback transactions at March 31, 2022 was $16.1 million, $3.8 million and $12.3 million of which was classified as short-term and long-term, respectively on the accompanying consolidated balance sheet. The outstanding balance of this obligation at December 31, 2021 was $17.0 million, $4.5 million and $12.5 million of which was classified as short-term and long-term, respectively on the accompanying consolidated balance sheets. The fair value of this finance obligation approximated the carrying value as of both March 31, 2022 and December 31, 2021. ​ Future minimum payments under finance obligations notes above as of March 31, 2022 were as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total ​ ​ Sale of Future ​ Sale/leaseback ​ Finance ​ ​ revenue - debt ​ financings ​ Obligations Remainder of 2022 ​ $ 49,193 ​ $ 3,582 ​ $ 52,775 2023 ​ ​ 65,591 ​ ​ 3,531 ​ ​ 69,122 2024 ​ ​ 65,591 ​ ​ 9,286 ​ ​ 74,877 2025 ​ ​ 60,334 ​ ​ 383 ​ ​ 60,717 2026 ​ ​ 43,611 ​ ​ 383 ​ ​ 43,994 2027 and thereafter ​ ​ 34,452 ​ ​ 556 ​ ​ 35,008 Total future minimum payments ​ ​ 318,772 ​ ​ 17,721 ​ ​ 336,493 Less imputed interest ​ ​ (74,678) ​ ​ (1,591) ​ ​ (76,269) Total ​ $ 244,094 ​ $ 16,130 ​ $ 260,224 ​ Other information related to the above finance obligations are presented in the following table: ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ Three months ended ​ March 31, 2022 ​ March 31, 2021 Cash payments (in thousands) $ 17,409 ​ $ 12,816 Weighted average remaining term (years) ​ 4.91 ​ ​ 4.90 Weighted average discount rate ​ 10.8% ​ ​ 11.2% ​

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2022
Commitments and Contingencies
Commitments and Contingencies	19. Commitments and Contingencies ​ Restricted Cash ​ In connection with certain of the above noted sale/leaseback agreements, cash of $252.6 million and $275.1 million was required to be restricted as security as of March 31, 2022 and December 31, 2021, respectively, which restricted cash will be released over the lease term. As of March 31, 2022 and December 31, 2021, the Company also had certain letters of credit backed by security deposits totaling $339.7 million and $286.0 million, respectively, that are security for the above noted sale/leaseback agreements. ​ As of both March 31, 2022 and December 31, 2021, the Company had $67.7 million held in escrow related to the construction of certain hydrogen plants. ​ The Company also had $5.0 million of consideration held by our paying agent in connection with the Applied Cryo acquisition reported as restricted cash as of March 31, 2022, with a corresponding accrued liability on the Company’s unaudited interim condensed consolidated balance sheet. Additionally, the Company had $15.3 million in restricted cash as collateral resulting from the Frames acquisition. ​ Litigation ​ Legal matters are defended and handled in the ordinary course of business. Liabilities for loss contingencies arising from claims, assessments, litigation, fines, and penalties and other sources are recorded when it is probable that a liability has been incurred and the amount can be reasonably estimated. Legal costs incurred in connection with loss contingencies are expensed as incurred. The Company has not recorded any accruals related to any legal matters. ​ Concentrations of Credit Risk ​ Financial instruments that potentially subject the Company to credit risk consist principally of cash, cash equivalents, restricted cash, accounts receivable and marketable securities. Cash and restricted cash are maintained in accounts with financial institutions, which, at times may exceed the Federal depository insurance coverage of $250 thousand. The Company has not experienced losses on these accounts and management believes, based upon the quality of the financial institutions, that the credit risk with regard to these deposits is not significant. The Company’s available-for-sale securities consists primarily of investments in U.S. Treasury securities and short-term high credit quality corporate debt securities. Equity securities are comprised of fixed income and equity market index mutual funds. ​ Concentrations of credit risk with respect to receivables exist due to the limited number of select customers with whom the Company has commercial sales arrangements. To mitigate credit risk, the Company performs appropriate evaluation of a prospective customer’s financial condition. ​ At March 31, 2022, two customers comprised 30.0% of the total accounts receivable balance. At December 31, 2021, one customer comprised approximately 46.6% of the total accounts receivable balance. ​ For purposes of assigning a customer to a sale/leaseback transaction completed with a financial institution, the Company considers the end user of the assets to be the ultimate customer. For the three months ended March 31, 2022, 67.0% of total consolidated revenues were associated with five customers. For the three months ended March 31, 2021, 71.2% of total consolidated revenues were associated primarily with three customers. ​

Employee Benefit Plans

Employee Benefit Plans	3 Months Ended
	Mar. 31, 2022
Employee Benefit Plans
Employee Benefit Plans	20. Employee Benefit Plans ​ 2011 and 2021 Stock Option and Incentive Plan ​ The Company has issued stock-based awards to employees and members of its Board of Directors (the “Board”) consisting of stock options and restricted stock awards. The Company accounts for all stock-based awards to employees and members of the Board as compensation costs in the consolidated financial statements based on their fair values measured as of the date of grant. These costs are recognized over the requisite service period. Stock-based compensation costs recognized, excluding the Company’s 401(k) match and quarterly board compensation, were $40.8 million and $8.5 million for the three months ended March 31, 2022 and March 31, 2021, respectively. The methods and assumptions used in the determination of the fair value of stock-based awards are consistent with those described in our 2021 Form 10-K. ​ Option Awards ​ The Company issues options that are time and performance-based awards. All option awards are determined to be classified as equity awards. ​ Service Stock Options Awards ​ The following table reflects the service stock option activity for the three months ended March 31, 2022: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ ​ ​ Weighted ​ Average ​ ​ ​ ​ ​ ​ ​ Average ​ Remaining ​ Aggregate ​ ​ ​ ​ Exercise ​ Contractual ​ Intrinsic ​ ​ Shares ​ Price ​ Terms ​ Value Options outstanding at December 31, 2021 ​ 9,786,909 ​ $ 11.65 ​ 7.7 ​ $ 172,412 Granted ​ 451,500 ​ ​ 23.83 ​ — ​ ​ — Exercised ​ (56,692) ​ ​ 5.13 ​ — ​ ​ — Forfeited ​ (16,717) ​ ​ 13.16 ​ — ​ ​ — Options outstanding at March 31, 2022 ​ 10,165,000 ​ $ 12.20 ​ 7.5 ​ $ 176,301 Options exercisable at March 31, 2022 ​ 4,900,538 ​ ​ 5.96 ​ 6.3 ​ ​ 114,080 Options unvested at March 31, 2022 ​ 5,264,462 ​ $ 18.03 ​ 8.7 ​ $ 62,221 ​ The weighted average grant-date fair value of the service stock options granted during the three months ended March 31, 2022 and 2021 was $15.34 and $31.78, respectively. The total intrinsic fair value of service stock options exercised during the three months ended March 31, 2022 and 2021 was $1.1 million and $1.0 million, respectively. The total fair value of the service stock options that vested during the three months ended March 31, 2022 and 2021 was approximately $5.6 million and $2.9 million, respectively. ​ Compensation cost associated with service stock options represented approximately $5.9 million and $3.3 million of the total share-based payment expense recorded for the three months ended March 31, 2022 and 2021, respectively. As of March 31, 2022 and 2021 there was approximately $47.0 million and $40.5 million, respectively, of unrecognized compensation cost related to service stock option awards to be recognized over the weighted average remaining period of 2.13 years. ​ Performance Stock Option Awards ​ Compensation cost associated with performance stock options represented approximately $25.1 million and $0 of the total share-based payment expense recorded for the three months ended March 31, 2022 and 2021, respectively. As of March 31, 2022, there was approximately $125.1 million of unrecognized compensation cost related to performance stock option awards to be recognized over the weighted average remaining period of 2.48 years. There were no new grants of performance stock option awards for the three months ended March 31, 2022. ​ Restricted Stock Awards ​ The Company recorded expense associated with its restricted stock awards of approximately $9.8 million and $5.2 million for the three months ended March 31, 2022 and 2021, respectively. Additionally, for the three months ended March 31, 2022 and 2021, there was $83.7 million and $64.1 million, respectively, of unrecognized compensation cost related to restricted stock awards to be recognized over the weighted average period of 2.1 years. ​ A summary of restricted stock activity for the three months ended March 31, 2022 is as follows (in thousands except share amounts): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted Aggregate ​ ​ ​ ​ Average Grant Date ​ Intrinsic ​ ​ ​ Shares ​ Fair Value ​ Value ​ Unvested restricted stock at December 31, 2021 ​ 4,851,873 ​ $ 21.59 ​ $ — ​ Granted ​ 802,500 ​ ​ 23.86 ​ ​ — ​ Vested ​ (196,832) ​ ​ 41.93 ​ ​ — ​ Forfeited ​ (18,334) ​ ​ 13.20 ​ ​ — ​ Unvested restricted stock at March 31, 2022 ​ 5,439,207 ​ $ 18.31 ​ $ 155,616 ​ ​ The weighted average grant-date fair value of the restricted stock awards granted during the three months ended March 31, 2022 and 2021, was $3.9 million and $457 thousand, respectively. The total fair value of restricted stock awards vested for the three months ended March 31, 2022, and 2021 were $23.86 million and $43.89 million, respectively. 401(k) Savings & Retirement Plan ​ The Company issued 96,539 shares of common stock and 12,513 shares of common stock pursuant to the Plug Power Inc. 401(k) Savings & Retirement Plan during the three months ended March 31, 2022 and 2021, respectively. ​ The Company’s expense for this plan was approximately $2.2 million, and $1.3 million for the three months ended March 31, 2022 and 2021, respectively. ​ Non-Employee Director Compensation ​ The Company granted 3,290 shares of common stock and 2,653 shares of common stock to non-employee directors as compensation for the three months ended March 31, 2022 and 2021, respectively. All common stock issued is fully vested at the time of issuance and is valued at fair value on the date of issuance. The Company’s share-based compensation expense in connection with non-employee director compensation was approximately $94 thousand and $85 thousand for the three months ended March 31, 2022 and 2021, respectively.

Segment Reporting

Segment Reporting	3 Months Ended
	Mar. 31, 2022
Segment Reporting
Segment Reporting	21. Segment Reporting ​ Our organization is managed from a sales perspective on the basis of “go-to-market” sales channels, emphasizing shared learning across end user applications and common supplier/vendor relationships. These sales channels are structured to serve a range of customers for our products and services. As a result of this structure, we concluded that we have one operating and reportable ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenues ​ Long-Lived Assets as of ​ Three Months Ended ​ Three Months Ended ​ March 31, 2022 ​ March 31, 2021 ​ ​ March 31, 2022 ​ December 31, 2021 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ North America $ 113,678 ​ $ 69,646 ​ ​ $ 665,992 ​ $ 570,778 Other ​ 27,126 ​ ​ 2,312 ​ ​ ​ 5,796 ​ ​ 2,778 Total $ 140,804 ​ $ 71,958 ​ ​ $ 671,788 ​ $ 573,556 ​

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2022
Subsequent Events
Subsequent Events	22. Subsequent Events ​ On

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2022
Summary of Significant Accounting Policies
Principles of Consolidation	Principles of Consolidation ​ The unaudited interim condensed consolidated financial statements include the financial statements of the Company and its wholly-owned subsidiaries. Intercompany balances and transactions have been eliminated in consolidation. In addition, we include our share of the results of HyVia, AccionaPlug S.L., and HALO Hydrogen Co, Ltd., using the equity method based on our economic ownership interest and our ability to exercise significant influence over the operating and financial decisions of HyVia, AccionaPlug S.L., and HALO Hydrogen Co, Ltd. ​
Interim Financial Statements	Interim Financial Statements ​ The accompanying unaudited interim condensed consolidated financial statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). In the opinion of management, all adjustments, which consist solely of normal recurring adjustments, necessary to present fairly, in accordance with U.S. generally accepted accounting principles (“GAAP”), the financial position, results of operations and cash flows for all periods presented, have been made. The results of operations for the interim periods presented are not necessarily indicative of the results that may be expected for the full year. ​ Certain information and footnote disclosures normally included in annual consolidated financial statements prepared in accordance with GAAP have been condensed or omitted. These unaudited interim condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2021 (the “2021 Form 10-K”). ​ The information presented in the accompanying unaudited interim condensed consolidated balance sheets as of December 31, 2021 has been derived from the Company’s December 31, 2021 audited consolidated financial statements. ​ The unaudited condensed consolidated financial statements contained herein should be read in conjunction with our 2021 Form 10-K .
Recent Accounting Pronouncements	Recent Accounting Pronouncements Recently Adopted Accounting Guidance ​ Other than the adoption of the accounting guidance mentioned i n our 2021 Form 10-K, ​ Recent Accounting Guidance Not Yet Effective ​ All issued but not yet effective accounting and reporting standards as of March 31, 2022 are either not applicable to the Company or are not expected to have a material impact on the Company.

Acquisitions (Tables)

Acquisitions (Tables)	3 Months Ended
	Mar. 31, 2022
Applied Cryo Technologies
Schedule of fair value of consideration paid	The fair value of consideration paid by the Company in connection with the Applied Cryo acquisition was as follows (in thousands): ​ ​ ​ ​ Cash $ 98,559 Plug Power Inc. Common Stock ​ 46,697 Contingent consideration ​ 14,000 Settlement of preexisting relationship ​ 2,837 Total consideration $ 162,093 ​
Summary of allocation of the purchase price to the estimated fair value of the net assets acquired	The following table summarizes the preliminary allocation of the purchase price to the estimated fair value of the net assets acquired, excluding goodwill (in thousands): ​ ​ ​ ​ Cash $ 1,180 Accounts receivable ​ 4,123 Inventory 24,655 Prepaid expenses and other assets ​ 1,506 Property, plant and equipment ​ 4,515 Right of use asset ​ 2,788 Identifiable intangible assets ​ 70,484 Lease liability ​ (2,672) Accounts payable, accrued expenses and other liabilities ​ (8,206) Deferred tax liability ​ (16,541) Deferred revenue ​ (12,990) Total net assets acquired, excluding goodwill $ 68,842 ​
Business combination segment allocation	The goodwill was primarily attributed to the value of synergies created with the Company’s current and future offerings and the value of the assembled workforce. Goodwill and intangible assets are not deductible for income tax purposes. Goodwill associated with the Applied Cryo acquisition was calculated as follows (in thousands): ​ ​ ​ ​ Consideration paid $ 162,093 Less: net assets acquired ​ (68,842) Total goodwill recognized $ 93,251
Frames Holding B.V.
Schedule of fair value of consideration paid	The fair value of consideration paid by the Company in connection with the Frames acquisition was as follows (in thousands): ​ ​ ​ ​ Cash $ 94,541 Contingent consideration ​ 29,057 Settlement of preexisting relationship ​ 4,263 Total consideration $ 127,861 ​
Summary of allocation of the purchase price to the estimated fair value of the net assets acquired	The following table summarizes the preliminary allocation of the purchase price to the estimated fair value of the total net assets acquired, excluding goodwill (in thousands): ​ ​ ​ ​ Cash $ 45,394 Accounts receivable ​ 17,910 Inventory 34 Prepaid expenses and other assets ​ 3,652 Property, plant and equipment ​ 709 Right of use asset ​ 1,937 Contract asset ​ 9,960 Identifiable intangible assets ​ 50,478 Lease liability ​ (1,937) Contract liability ​ (22,737) Accounts payable, accrued expenses and other liabilities ​ (18,465) Deferred tax liability ​ (4,105) Provision for loss contracts ​ (2,636) Warranty provisions ​ (7,566) Total net assets acquired, excluding goodwill $ 72,628 ​
Business combination segment allocation	The goodwill was primarily attributed to the value of synergies created with the Company’s current and future offerings and the value of the assembled workforce. Goodwill and intangible assets are not deductible for income tax purposes. Goodwill associated with the Frames acquisition was calculated as follows (in thousands): ​ ​ ​ ​ Consideration paid $ 127,861 Less: net assets acquired ​ (72,628) Total goodwill recognized $ 55,233 ​
Joule Processing LLC
Schedule of fair value of consideration paid	The fair value of consideration paid by the Company in connection with the Joule acquisition was as follows (in thousands): ​ ​ ​ ​ Cash $ 28,140 Contingent consideration ​ 41,732 Total consideration $ 69,872 ​ ​
Summary of allocation of the purchase price to the estimated fair value of the net assets acquired	The following table summarizes the preliminary allocation of the purchase price to the estimated fair value of the net assets acquired, excluding goodwill (in thousands): ​ ​ ​ ​ Current assets $ 2,672 Property, plant and equipment ​ 493 Right of use asset ​ 182 Identifiable intangible assets ​ 60,522 Lease liability ​ (374) Current liabilities ​ (2,748) Contract liability ​ (3,818) Total net assets acquired, excluding goodwill $ 56,929
Business combination segment allocation	The goodwill was primarily attributed to the value of synergies created with the Company’s current and future offerings and the value of the assembled workforce. Goodwill and intangible assets are not deductible for income tax purposes. Goodwill associated with the Joule acquisition was calculated as follows (in thousands): ​ ​ ​ ​ Consideration paid $ 28,140 Contingent consideration ​ 41,732 Less: net assets acquired ​ (56,929) Total goodwill recognized $ 12,943

Extended Maintenance Contracts

Extended Maintenance Contracts (Tables)	3 Months Ended
	Mar. 31, 2022
Extended Maintenance Contracts
Schedule of accrual for loss contracts	​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ Year ended ​ March 31, 2022 ​ December 31, 2021 Beginning balance $ 89,773 ​ $ 24,013 Provision for loss accrual ​ 2,048 ​ ​ 71,988 Loss accrual from acquisition ​ — ​ ​ 2,636 Releases to service cost of sales ​ (9,345) ​ ​ (8,864) Ending balance $ 82,476 ​ $ 89,773

Earnings Per Share (Tables)

Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2022
Earnings Per Share
Schedule of potential dilutive common shares	​ ​ ​ ​ ​ ​ ​ ​ At March 31, ​ 2022 2021 Stock options outstanding (1) ​ 24,185,000 9,020,891 Restricted stock outstanding (2) ​ 5,439,207 6,416,308 Common stock warrants (3) ​ 80,017,181 ​ 88,264,726 Convertible Senior Notes (4) ​ 39,170,766 39,170,766 Number of dilutive potential shares of common stock ​ 148,812,154 142,872,691 ​ (1) During the three months ended March 31, 2022 and 2021, the Company granted options for 451,500 and 581,000 shares of common stock, respectively. ​ (2) During the three months ended March 31, 2022 and 2021, the Company granted 802,500 and 555,000 restricted shares of common stock, respectively. ​ (3) In April 2017, the Company issued a warrant to acquire up to 55,286,696 shares of the Company’s common stock as part of a transaction agreement with Amazon, subject to certain vesting events, as described in Note 12, “Warrant Transaction Agreements.” The warrant had been exercised with respect to 17,461,994 and 9,214,449 shares of the Company’s common stock as of March 31, 2022 and 2021, respectively. ​ In July 2017, the Company issued a warrant to acquire up to 55,286,696 shares of the Company’s common stock as part of a transaction agreement with Walmart, subject to certain vesting events, as described in Note 12, “Warrant Transaction Agreements.” The warrant had been exercised with respect to 13,094,217 shares of the Company’s common stock as of March 31, 2022 and 2021. ​ (4) In March 2018, the Company issued $100.0 million in aggregate principal amount of the 5.5% Convertible Senior Notes due 2023 (the “5.5% Convertible Senior Notes”). In May 2020, the Company repurchased $66.3 million of the 5.5% Convertible Senior Notes and in the fourth quarter of 2020, $33.5 million of the 5.5% Convertible Senior Notes were converted into approximately 14.6 million shares of common stock. The remaining $160.0 thousand aggregate principal amount of the 5.5% Convertible Senior Notes were converted into 69,808 shares of common stock in January 2021. In September 2019, the Company issued $40.0 million in aggregate principal amount of the 7.5% Convertible Senior Note due 2023 (the “7.5% Convertible Senior Note”), which was fully converted into 16.0 million shares of common stock on July 1, 2020. In May 2020, the Company issued $212.5 million in aggregate principal amount of the 3.75% Convertible Senior Notes. There were no conversions for the three months ended March 31, 2022. For the three months ended March 31, 2021, $15.2 million of the 3.75% Convertible Senior Notes were converted, resulting in the issuance of 3,016,036 shares of common stock.

Inventory (Tables)

Inventory (Tables)	3 Months Ended
	Mar. 31, 2022
Inventory
Schedule of Inventory	Inventory as of March 31, 2022 and December 31, 2021 consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, December 31, ​ ​ 2022 ​ 2021 ​ Raw materials and supplies - production locations ​ $ 247,100 ​ $ 187,449 ​ Raw materials and supplies - customer locations ​ ​ 14,301 ​ ​ 16,294 ​ Work-in-process ​ 62,558 ​ 58,341 ​ Finished goods ​ 9,420 ​ 7,079 ​ Inventory ​ $ 333,379 ​ $ 269,163 ​

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	3 Months Ended
	Mar. 31, 2022
Property, Plant and Equipment
Schedule of Property plant and equipment	Property, plant and equipment at March 31, 2022 and December 31, 2021 consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2022 ​ December 31, 2021 Land ​ $ 1,165 ​ $ 1,165 Construction in progress ​ ​ 235,548 ​ ​ 169,415 Leasehold improvements ​ ​ 2,645 ​ ​ 2,099 Software, machinery, and equipment ​ 116,974 ​ 112,068 Property, plant, and equipment ​ 356,332 ​ 284,747 Less: accumulated depreciation ​ (31,679) ​ (29,124) Property, plant, and equipment, net ​ $ 324,653 ​ $ 255,623

Intangible Assets and Goodwill

Intangible Assets and Goodwill (Tables)	3 Months Ended
	Mar. 31, 2022
Intangible Assets and Goodwill
Schedule of Intangible assets	The gross carrying amount and accumulated amortization of the Company’s acquired identifiable intangible assets as of March 31, 2022 were as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted Average ​ Gross Carrying ​ Accumulated ​ ​ ​ ​ ​ ​ Amortization Period ​ Amount ​ Amortization ​ Total Acquired technology 14 years $ 104,605 ​ $ (7,121) ​ $ 97,484 ​ Dry stack electrolyzer technology ​ 5 years ​ ​ 29,000 ​ ​ (483) ​ ​ 28,517 ​ Customer relationships, Non-compete agreements, Backlog & Trademark ​ 12 years ​ 90,811 ​ ​ (4,405) ​ ​ 86,406 ​ ​ ​ ​ ​ $ 224,416 ​ $ (12,009) ​ $ 212,407 ​ ​ The gross carrying amount and accumulated amortization of the Company’s acquired identifiable intangible assets as of December 31, 2021 were as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted Average ​ Gross Carrying ​ Accumulated ​ ​ ​ ​ ​ ​ Amortization Period ​ Amount ​ Amortization ​ Total Acquired technology 13 years ​ $ 45,530 ​ $ (5,392) ​ $ 40,138 ​ Customer relationships, Non-compete agreements, Backlog & Trademark ​ 12 years ​ ​ 90,497 ​ ​ (1,427) ​ ​ 89,070 ​ In process research and development Indefinite ​ 29,000 ​ ​ — ​ 29,000 ​ ​ ​ ​ ​ $ 165,027 ​ $ (6,819) ​ $ 158,208 ​
Schedule of future amortization of intangible assets	The estimated amortization expense for subsequent years is as follows (in thousands): ​ ​ ​ ​ ​ Remainder of 2022 $ 18,743 2023 ​ ​ 21,189 2024 ​ ​ 21,131 2025 ​ ​ 20,353 2026 ​ ​ 18,797 2027 and thereafter ​ ​ 112,194 Total ​ $ 212,407
Schedule of changes in the carrying amount of goodwill	​ ​ ​ ​ ​ Remainder of 2022 $ 18,743 2023 ​ ​ 21,189 2024 ​ ​ 21,131 2025 ​ ​ 20,353 2026 ​ ​ 18,797 2027 and thereafter ​ ​ 112,194 Total ​ $ 212,407

Convertible Senior Notes (Table

Convertible Senior Notes (Tables) - 3.75% Convertible Senior Notes	3 Months Ended
	Mar. 31, 2022
Debt Instrument [Line Items]
Schedule of Convertible Senior Notes	The 3.75% Convertible Senior Notes consisted of the following (in thousands): ​ ​ ​ ​ ​ March 31, ​ 2022 Principal amounts: ​ ​ Principal $ 197,278 Unamortized debt issuance costs (1) ​ (4,329) Net carrying amount $ 192,949 1) Included in the unaudited interim condensed consolidated balance sheets within the 3.75% Convertible Senior Notes, net and amortized over the remaining life of the notes using the effective interest rate method. ​
Schedule of debt	The following table summarizes the total interest expense and effective interest rate related to the 3.75% Convertible Senior Notes (in thousands, except for effective interest rate): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ ​ March 31, ​ ​ 2022 ​ 2021 ​ Interest expense ​ $ 1,849 ​ $ 1,897 ​ Amortization of debt issuance costs ​ ​ 316 ​ ​ 1,258 ​ Total ​ ​ 2,165 ​ ​ 3,155 ​ ​ ​ ​ ​ ​ ​ ​ ​ Effective interest rate ​ ​ 4.5% ​ ​ 4.5% ​ ​

Revenue (Tables)

Revenue (Tables)	3 Months Ended
	Mar. 31, 2022
Revenue
Schedule of disaggregation of revenue	The following table provides information about disaggregation of revenue (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ Major products/services lines ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended March 31, ​ ​ ​ 2022 ​ 2021 ​ Sales of fuel cell systems ​ $ 37,528 ​ $ 26,419 ​ Sales of hydrogen infrastructure ​ ​ 27,089 ​ ​ 20,353 ​ Sales of electolyzers ​ ​ 4,059 ​ ​ — ​ Sales of oil and gas equipment ​ ​ 21,968 ​ ​ — ​ Services performed on fuel cell systems and related infrastructure ​ ​ 8,240 ​ ​ 6,045 ​ Power Purchase Agreements ​ ​ 10,037 ​ ​ 7,826 ​ Fuel delivered to customers ​ ​ 13,429 ​ ​ 11,127 ​ Sales of cryogenic equipment ​ ​ 18,203 ​ ​ — ​ Other ​ ​ 251 ​ ​ 188 ​ Net revenue ​ $ 140,804 ​ $ 71,958 ​ ​
Schedule of receivables, contract assets and contract liabilities from contracts with customers	The following table provides information about receivables, contract assets and contract liabilities from contracts with customers (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ ​ 2022 ​ 2021 Accounts receivable ​ $ 57,322 ​ $ 92,675 Contract assets ​ ​ 38,713 ​ ​ 38,757 Contract liabilities ​ ​ 155,185 ​ ​ 183,090
Schedule of changes in contract assets and the contract liabilities	Significant changes in the contract assets and the contract liabilities balances during the period are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Contract assets ​ Three months ended ​ ​ March 31, 2022 ​ December 31, 2021 Transferred to receivables from contract assets recognized at the beginning of the period ​ $ (3,693) ​ $ (14,638) Contract assets assumed as part of acquisition ​ ​ — ​ ​ 9,960 Revenue recognized and not billed as of the end of the period ​ ​ 3,649 ​ ​ 25,246 Net change in contract assets ​ $ (44) ​ $ 20,568 ​ ​ ​ ​ ​ ​ ​ ​ ​ Contract liabilities ​ Three months ended ​ ​ March 31, 2022 ​ December 31, 2021 Increases due to cash received, net of amounts recognized as revenue during the period ​ $ 13,327 ​ $ 182,052 Contract liabilities assumed as part of acquisitions ​ ​ 3,818 ​ ​ 35,727 Revenue recognized that was included in the contract liability balance as of the beginning of the period ​ ​ (45,050) ​ ​ (110,974) Net change in contract liabilities ​ $ (27,905) ​ $ 106,805 ​
Schedule of Estimated future revenue	The following table includes estimated revenue included in the backlog expected to be recognized in the future (sales of fuel cell systems and hydrogen Power Purchase five ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ ​ 2022 Sales of fuel cell systems ​ $ 16,466 Sale of hydrogen installations and other infrastructure ​ ​ 40,487 Sale of electrolyzers ​ ​ 51,267 Sales of oil and gas equipment ​ ​ 73,270 Services performed on fuel cell systems and related infrastructure ​ ​ 98,635 Power Purchase Agreements ​ ​ 255,929 Fuel delivered to customers and related equipment ​ ​ 83,796 Sale of cryogenic equipment ​ ​ 62,299 Total estimated future revenue ​ $ 682,149

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2022
Fair Value Measurements
Schedule of assets and liabilities measured at fair value on a recurring basis that have unobservable inputs	​ ​ ​ ​ ​ ​ ​ ​ Financial Instrument Fair Value Valuation Technique Unobservable Input Range (weighted average) Contingent Consideration ​ $ 89,670 Scenario based method Credit spread 12.34% - 13.77% (13.06%) ​ ​ ​ ​ ​ Discount rate 13.84% - 16.06% (14.95%) ​ ​ ​ 10,400 Monte carlo simulation Credit spread 12.50% ​ ​ ​ ​ ​ Discount rate 14.63% ​ ​ ​ ​ ​ Revenue volatility 57.24% (35.0%) ​ ​ ​ 3,149 Monte carlo simulation Credit spread 13.00% - 13.08% (12.92%) ​ ​ ​ ​ ​ Revenue volatility 47.7% - 25.9% (35.0%) ​ ​ ​ ​ ​ Gross profit volatility 113.9% - 24.2% (70.0%) ​ ​ ​ 103,219 ​ ​ ​
Schedule of assets and liabilities measured at fair value on a recurring basis	Assets and liabilities measured at fair value on a recurring basis are summarized below (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of March 31, 2022 ​ ​ Carrying ​ Fair ​ Fair Value Measurements ​ ​ Amount ​ Value ​ Level 1 ​ Level 2 ​ Level 3 Assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash equivalents $ 37,116 $ 37,116 $ 37,116 $ — $ — Corporate bonds ​ 244,921 ​ 244,921 ​ — ​ 244,921 ​ — U.S. Treasuries ​ 554,307 ​ 554,307 ​ 554,307 ​ — ​ — Equity securities ​ 147,826 ​ 147,826 ​ 147,826 ​ — ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Contingent consideration ​ 103,219 ​ 103,219 ​ — ​ — ​ 103,219 Swaps and forward contracts ​ 371 ​ (1,165) ​ 1,165 ​ — ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2021 ​ ​ Carrying ​ Fair ​ Fair Value Measurements ​ ​ Amount ​ Value ​ Level 1 ​ Level 2 ​ Level 3 Assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash equivalents $ 115,241 $ 115,241 $ 115,241 $ — $ — Corporate bonds ​ 226,382 ​ 226,382 ​ — ​ 226,382 ​ — U.S. Treasuries ​ 1,013,883 ​ 1,013,883 ​ 1,013,883 ​ — ​ — Equity securities ​ 147,995 ​ 147,995 ​ 147,995 ​ — ​ — Swaps and forward contracts ​ 70 ​ 70 ​ 70 ​ — ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Contingent consideration ​ 62,297 ​ 62,297 ​ — ​ — ​ 62,297 Swaps and forward contracts ​ 981 ​ 981 ​ 981 ​ — ​ —
Schedule of activity in the level 3 liabilities	The change in the carrying amount of Level 3 liabilities for the three month period ended March 31, 2022 was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ Three months ended ​ ​ ​ March 31, 2022 Beginning balance at December 31, 2021 ​ $ 62,297 Payments ​ ​ (2,667) Additions due to acquisitions ​ ​ 41,732 Fair value adjustments ​ ​ 2,461 Gain due to currency translation ​ (604) Ending balance at March 31, 2022 ​ $ 103,219

Investments (Tables)

Investments (Tables)	3 Months Ended
	Mar. 31, 2022
Investments
Schedule of gross unrealized gains and losses, and the amortized cost, allowance for credit losses, and fair value of those investments classified as available-for-sale	The amortized cost, gross unrealized gains and losses, fair value of those investments classified as available-for-sale, and allowance for credit losses at March 31, 2022 are summarized as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2022 ​ Amortized ​ Gross ​ Gross ​ Fair ​ Allowance for ​ Cost ​ Unrealized Gains ​ Unrealized Losses ​ Value ​ Credit Losses Corporate bonds $ 251,827 ​ $ — ​ $ (6,906) ​ $ 244,921 ​ ​ — U.S. Treasuries ​ 565,149 ​ ​ — ​ ​ (10,842) ​ ​ 554,307 ​ ​ — Total $ 816,976 ​ $ — ​ $ (17,748) ​ $ 799,228 ​ $ — ​ The amortized cost, gross unrealized gains and losses, fair value of those investments classified as available-for-sale, and allowance for credit losses at December 31, 2021 are summarized as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ Amortized ​ Gross ​ Gross ​ Fair ​ Allowance for ​ Cost ​ Unrealized Gains ​ Unrealized Losses ​ Value ​ Credit Losses Corporate bonds $ 228,614 ​ $ — ​ $ (2,232) ​ $ 226,382 ​ ​ — U.S. Treasuries ​ 1,014,319 ​ ​ 20 ​ ​ (456) ​ ​ 1,013,883 ​ ​ — Total $ 1,242,933 ​ $ 20 ​ $ (2,688) ​ $ 1,240,265 ​ $ —
Schedule of investments classified as equity securities	The cost, gross unrealized gains and losses, and fair value of those investments classified as equity securities at March 31, 2022 are summarized as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2022 ​ ​ ​ ​ Gross ​ Gross ​ Fair ​ ​ Cost ​ Unrealized Gains ​ Unrealized Losses ​ Value Fixed income mutual funds $ 70,247 $ — ​ $ (1,772) ​ $ 68,475 Exchange traded mutual funds ​ 76,000 ​ ​ 3,351 ​ ​ — ​ ​ 79,351 Total $ 146,247 ​ $ 3,351 ​ $ (1,772) ​ $ 147,826 ​ The cost, gross unrealized gains and losses, and fair value of those investments classified as equity securities at December 31, 2021 are summarized as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ ​ ​ ​ Gross ​ Gross ​ Fair ​ ​ Cost ​ Unrealized Gains ​ Unrealized Losses ​ Value Fixed income mutual funds $ 70,247 $ — ​ $ (574) ​ $ 69,673 Exchange traded mutual funds ​ 71,010 ​ ​ 7,312 ​ ​ — ​ ​ 78,322 Total $ 141,257 ​ $ 7,312 ​ $ (574) ​ $ 147,995
Schedule of the amortized cost and fair value of investments classified as available-for-sale, by contractual maturity	A summary of the amortized cost and fair value of investments classified as available-for-sale, by contractual maturity, as of March 31, 2022 and December 31, 2021 was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2022 ​ December 31, 2021 ​ ​ Amortized ​ Fair ​ ​ Amortized ​ Fair Maturity: ​ Cost ​ Value ​ ​ Cost ​ Value Within one year $ 307,565 $ 305,681 ​ $ 670,584 $ 670,306 After one through five years 509,411 ​ 493,547 ​ 572,349 ​ 569,959 Total $ 816,976 ​ $ 799,228 ​ $ 1,242,933 ​ $ 1,240,265

Operating and Finance Lease L_2

Operating and Finance Lease Liabilities (Tables)	3 Months Ended
	Mar. 31, 2022
Operating and Finance Lease Liabilities
Schedule of future minimum lease payments under operating leases	Future minimum lease payments under operating and finance leases (with initial or remaining lease terms in excess of one year) as of March 31, 2022 were as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Finance ​ Total ​ ​ Operating Lease ​ Lease ​ Lease ​ ​ Liability ​ Liability ​ Liabilities Remainder of 2022 ​ $ 42,373 ​ $ 5,929 ​ $ 48,302 2023 ​ ​ 56,034 ​ 7,800 ​ ​ 63,834 2024 ​ ​ 54,667 ​ 7,773 ​ ​ 62,440 2025 ​ ​ 50,800 ​ 10,671 ​ ​ 61,471 2026 ​ ​ 43,515 ​ ​ 8,039 ​ ​ 51,554 2027 and thereafter ​ ​ 43,652 ​ ​ 2,343 ​ ​ 45,995 Total future minimum payments ​ ​ 291,041 ​ 42,555 ​ ​ 333,596 Less imputed interest ​ ​ (71,350) ​ ​ (6,381) ​ ​ (77,731) Total ​ $ 219,691 ​ $ 36,174 ​ $ 255,865
Schedule of operating leases other information	​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ Three months ended ​ March 31, 2022 ​ March 31, 2021 Cash payments (in thousands) $ 13,547 ​ $ 6,734 Weighted average remaining lease term (years) ​ 5.46 ​ ​ 5.77 Weighted average discount rate ​ 10.9% ​ ​ 11.6%
Schedule of finance leases other information	​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ Three months ended ​ March 31, 2022 ​ March 31, 2021 Cash payments (in thousands) $ 1,868 ​ $ 433 Weighted average remaining lease term (years) ​ 4.44 ​ ​ 5.10 Weighted average discount rate ​ 6.5% ​ ​ 7.2%

Finance Obligation (Tables)

Finance Obligation (Tables)	3 Months Ended
	Mar. 31, 2022
Sale Leaseback Transaction [Line Items]
Schedule of finance leases other information	​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ Three months ended ​ March 31, 2022 ​ March 31, 2021 Cash payments (in thousands) $ 1,868 ​ $ 433 Weighted average remaining lease term (years) ​ 4.44 ​ ​ 5.10 Weighted average discount rate ​ 6.5% ​ ​ 7.2%
Finance obligation
Sale Leaseback Transaction [Line Items]
Schedule of future minimum lease payments under finance obligations	Future minimum payments under finance obligations notes above as of March 31, 2022 were as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total ​ ​ Sale of Future ​ Sale/leaseback ​ Finance ​ ​ revenue - debt ​ financings ​ Obligations Remainder of 2022 ​ $ 49,193 ​ $ 3,582 ​ $ 52,775 2023 ​ ​ 65,591 ​ ​ 3,531 ​ ​ 69,122 2024 ​ ​ 65,591 ​ ​ 9,286 ​ ​ 74,877 2025 ​ ​ 60,334 ​ ​ 383 ​ ​ 60,717 2026 ​ ​ 43,611 ​ ​ 383 ​ ​ 43,994 2027 and thereafter ​ ​ 34,452 ​ ​ 556 ​ ​ 35,008 Total future minimum payments ​ ​ 318,772 ​ ​ 17,721 ​ ​ 336,493 Less imputed interest ​ ​ (74,678) ​ ​ (1,591) ​ ​ (76,269) Total ​ $ 244,094 ​ $ 16,130 ​ $ 260,224
Schedule of finance leases other information	​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ Three months ended ​ March 31, 2022 ​ March 31, 2021 Cash payments (in thousands) $ 17,409 ​ $ 12,816 Weighted average remaining term (years) ​ 4.91 ​ ​ 4.90 Weighted average discount rate ​ 10.8% ​ ​ 11.2%

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	3 Months Ended
	Mar. 31, 2022
Nonvested Restricted Stock Shares Activity	A summary of restricted stock activity for the three months ended March 31, 2022 is as follows (in thousands except share amounts): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted Aggregate ​ ​ ​ ​ Average Grant Date ​ Intrinsic ​ ​ ​ Shares ​ Fair Value ​ Value ​ Unvested restricted stock at December 31, 2021 ​ 4,851,873 ​ $ 21.59 ​ $ — ​ Granted ​ 802,500 ​ ​ 23.86 ​ ​ — ​ Vested ​ (196,832) ​ ​ 41.93 ​ ​ — ​ Forfeited ​ (18,334) ​ ​ 13.20 ​ ​ — ​ Unvested restricted stock at March 31, 2022 ​ 5,439,207 ​ $ 18.31 ​ $ 155,616 ​
Service Options Awards
Schedule of Share-based Compensation, Stock Options, Activity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ ​ ​ Weighted ​ Average ​ ​ ​ ​ ​ ​ ​ Average ​ Remaining ​ Aggregate ​ ​ ​ ​ Exercise ​ Contractual ​ Intrinsic ​ ​ Shares ​ Price ​ Terms ​ Value Options outstanding at December 31, 2021 ​ 9,786,909 ​ $ 11.65 ​ 7.7 ​ $ 172,412 Granted ​ 451,500 ​ ​ 23.83 ​ — ​ ​ — Exercised ​ (56,692) ​ ​ 5.13 ​ — ​ ​ — Forfeited ​ (16,717) ​ ​ 13.16 ​ — ​ ​ — Options outstanding at March 31, 2022 ​ 10,165,000 ​ $ 12.20 ​ 7.5 ​ $ 176,301 Options exercisable at March 31, 2022 ​ 4,900,538 ​ ​ 5.96 ​ 6.3 ​ ​ 114,080 Options unvested at March 31, 2022 ​ 5,264,462 ​ $ 18.03 ​ 8.7 ​ $ 62,221

Segment Reporting (Tables)

Segment Reporting (Tables)	3 Months Ended
	Mar. 31, 2022
Segment Reporting
Schedule of revenue from external customers and long-lived assets, by geographical areas	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenues ​ Long-Lived Assets as of ​ Three Months Ended ​ Three Months Ended ​ March 31, 2022 ​ March 31, 2021 ​ ​ March 31, 2022 ​ December 31, 2021 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ North America $ 113,678 ​ $ 69,646 ​ ​ $ 665,992 ​ $ 570,778 Other ​ 27,126 ​ ​ 2,312 ​ ​ ​ 5,796 ​ ​ 2,778 Total $ 140,804 ​ $ 71,958 ​ ​ $ 671,788 ​ $ 573,556

Acquisitions - Fair value of co

Acquisitions - Fair value of consideration (Details) - USD ($) $ in Thousands	Jan. 14, 2022	Dec. 09, 2021	Nov. 22, 2021	Mar. 31, 2022
Consideration held by paying agent.				$ 5,000
Applied Cryo Technologies
Cash			$ 98,559
Plug Power Stock			46,697
Contingent consideration			14,000
Settlement of preexisting relationship			2,837
Total consideration			162,093
Consideration held by paying agent.			$ 5,000
Frames Holding B.V.
Cash		$ 94,541
Contingent consideration		29,057
Settlement of preexisting relationship		4,263
Total consideration		$ 127,861
Joule Processing LLC
Cash	$ 28,140
Contingent consideration	41,732
Total consideration	$ 69,872

Acquisitions - Allocation of Pu

Acquisitions - Allocation of Purchase Price (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Jan. 14, 2022	Dec. 31, 2021	Dec. 09, 2021	Nov. 22, 2021
Applied Cryo Technologies
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Cash					$ 1,180
Accounts receivable					4,123
Inventory					24,655
Prepaid expenses and other assets					1,506
Property, plant and equipment					4,515
Right of use asset					2,788
Identifiable intangible assets					70,484
Lease liability					(2,672)
Accounts payable, accrued expenses and other liabilities					(8,206)
Deferred tax liability			$ (16,500)		(16,541)
Deferred revenue					(12,990)
Total net assets acquired, excluding goodwill					$ 68,842
Frames Holding B.V.
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Cash				$ 45,394
Accounts receivable				17,910
Inventory				34
Prepaid expenses and other assets				3,652
Property, plant and equipment				709
Right of use asset				1,937
Contract asset				9,960
Identifiable intangible assets				50,478
Lease liability				(1,937)
Contact liability				(22,737)
Accounts payable, accrued expenses and other liabilities				(18,465)
Deferred tax liability	$ (4,100)			(4,105)
Provision for loss contracts				(2,636)
Warranty provisions				(7,566)
Total net assets acquired, excluding goodwill				$ 72,628
Joule Processing LLC
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Current assets		$ 2,672
Property, plant and equipment		493
Right of use asset		182
Identifiable intangible assets		60,522
Lease liability		(374)
Current liabilities		(2,748)
Contact liability		(3,818)
Total net assets acquired, excluding goodwill		$ 56,929

Acquisitions - Goodwill (Detail

Acquisitions - Goodwill (Details) - USD ($) $ in Thousands	Jan. 14, 2022	Dec. 09, 2021	Nov. 22, 2021	Mar. 31, 2022	Dec. 31, 2021
Total goodwill recognized				$ 232,031	$ 220,436
Applied Cryo Technologies
Consideration paid			$ 98,559
Contingent consideration			14,000
Consideration paid			162,093
Less: net assets acquired			(68,842)
Total goodwill recognized			$ 93,251
Frames Holding B.V.
Consideration paid		$ 94,541
Contingent consideration		29,057
Consideration paid		127,861
Less: net assets acquired		(72,628)
Total goodwill recognized		$ 55,233
Joule Processing LLC
Consideration paid	$ 28,140
Contingent consideration	41,732
Consideration paid	69,872
Less: net assets acquired	(56,929)
Total goodwill recognized	$ (12,943)

Acquisitions - Narratives (Deta

Acquisitions - Narratives (Details) $ in Thousands, € in Millions	Jan. 14, 2022USD ($)	Dec. 09, 2021USD ($)installment	Nov. 22, 2021USD ($)	Mar. 31, 2022USD ($)	Mar. 31, 2021USD ($)	Dec. 31, 2021USD ($)	Dec. 09, 2021EUR (€)
Change in fair value				$ 2,461	$ 790
Joule Processing LLC
Earn-out payments	$ 130,000			41,700
Achievement of revenue targets	90,000
Achievement of cost targets	40,000
Acquired	60,522
Change in fair value				0
Revenues				1,400
Joule Processing LLC | Developed Technology Rights
Acquired	$ 59,200
Estimated useful lives of acquired finite-lived intangible assets	15 years
Joule Processing LLC | Trade Names
Acquired	$ 800
Estimated useful lives of acquired finite-lived intangible assets	4 years
Joule Processing LLC | Noncompete Agreements
Acquired	$ 500
Estimated useful lives of acquired finite-lived intangible assets	6 years
Applied Cryo Technologies
Percentage of outstanding shares			100.00%
Earn-out payments			$ 30,000	14,000
Achievement of revenue targets			15,000
Achievement of cost targets			15,000
Acquired			70,484
Fair value of contingent consideration				14,100
Change in fair value				100
Deferred tax liability			16,541			$ 16,500
Reduction to valuation allowance						16,500
Deferred tax benefit						$ 16,500
Revenues				16,900
Applied Cryo Technologies | Developed Technology Rights
Acquired			$ 26,300
Estimated useful lives of acquired finite-lived intangible assets			15 years
Applied Cryo Technologies | Customer Relationships
Acquired			$ 26,600
Estimated useful lives of acquired finite-lived intangible assets			15 years
Applied Cryo Technologies | Trade Names
Acquired			$ 13,700
Estimated useful lives of acquired finite-lived intangible assets			15 years
Applied Cryo Technologies | Noncompete Agreements
Acquired			$ 1,000
Estimated useful lives of acquired finite-lived intangible assets			3 years
Applied Cryo Technologies | Customer Backlog
Acquired			$ 2,900
Estimated useful lives of acquired finite-lived intangible assets			1 year
Frames Holding B.V.
Percentage of outstanding shares		100.00%					100.00%
Earn-out payments | €							€ 30
Achievement of cost targets				29,100
Acquired		$ 50,478
Contingent consideration, number of installments | installment		2
Fair value of contingent consideration				29,400
Change in fair value				300
Deferred tax liability		$ 4,105		4,100
Revenues				$ 22,000
Frames Holding B.V. | Developed Technology Rights
Estimated useful lives of acquired finite-lived intangible assets		8 years
Fair value of acquisition		$ 5,300
Frames Holding B.V. | Customer Relationships
Fair value of acquisition		$ 27,200
Frames Holding B.V. | Customer Relationships | MPEEM approach
Estimated useful lives of acquired finite-lived intangible assets		17 years
Frames Holding B.V. | Trade Names
Estimated useful lives of acquired finite-lived intangible assets		8 years
Fair value of acquisition		$ 11,600
Frames Holding B.V. | Noncompete Agreements
Estimated useful lives of acquired finite-lived intangible assets		4 years
Fair value of acquisition		$ 4,900
Frames Holding B.V. | Backlog
Estimated useful lives of acquired finite-lived intangible assets		1 year
Fair value of acquisition		$ 1,400

Extended Maintenance Contract_2

Extended Maintenance Contracts (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Accrual for loss contracts
Beginning balance	$ 89,773	$ 24,013
Provision for loss accrual	2,048	71,988
Loss accrual from acquisition		2,636
Releases to service cost of sales	(9,345)	(8,864)
Ending balance	$ 82,476	$ 89,773

Earnings Per Share - Dilutive P

Earnings Per Share - Dilutive Potential Common Shares (Details) - USD ($) $ in Thousands	1 Months Ended				3 Months Ended			12 Months Ended
	Jan. 31, 2021	Nov. 30, 2020	Aug. 31, 2020	Sep. 30, 2019	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2021	May 31, 2020	May 29, 2020	May 18, 2020	Mar. 31, 2018	Jul. 20, 2017	Apr. 04, 2017
Earnings Per Share
Number of dilutive potential common stock					148,812,154	142,872,691
Common stock shares issued		43,700,000	35,276,250
3.75% Convertible Senior Notes
Earnings Per Share
Principal amount					$ 197,278	$ 15,200			$ 212,500	$ 12,500	$ 200,000
Conversion of notes through common stock issuance					0	3,016,036
Interest rate (as a percent)					3.75%	3.75%			3.75%	3.75%	3.75%
7.5% Convertible Senior Note
Earnings Per Share
Principal amount				$ 40,000
Conversion of notes through common stock issuance				16,000,000
Interest rate (as a percent)				7.50%		7.50%
5.5% Convertible Senior Notes
Earnings Per Share
Principal amount	$ 160						$ 33,500					$ 100,000
Conversion of notes through common stock issuance	69,808						14,600,000
Repurchase amount									$ 66,300
Interest rate (as a percent)	5.50%					5.50%	5.50%		5.50%			5.50%
Warrants issued in July 2017
Earnings Per Share
Number of warrants exercised (in shares)					13,094,217	13,094,217
Warrants issued with the Amazon, Inc transaction agreement
Earnings Per Share
Shares of common stock that can be purchased from warrants issued (in shares)														55,286,696
Number of warrants exercised (in shares)					17,461,994	9,214,449
Warrants issued with the Walmart Stores, Inc transaction agreement
Earnings Per Share
Shares of common stock that can be purchased from warrants issued (in shares)													55,286,696
Number of warrants exercised (in shares)					0	7,274,565		13,094,217
Stock options outstanding
Earnings Per Share
Number of dilutive potential common stock					24,185,000	9,020,891
Options granted					451,500	581,000
Restricted stock outstanding
Earnings Per Share
Number of dilutive potential common stock					5,439,207	6,416,308
Options granted					802,500	555,000
Common stock warrants
Earnings Per Share
Number of dilutive potential common stock					80,017,181	88,264,726
Convertible senior notes
Earnings Per Share
Number of dilutive potential common stock					39,170,766	39,170,766

Inventory (Details)

Inventory (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Inventory
Raw materials and supplies - production locations	$ 247,100	$ 187,449
Raw materials and supplies - customer locations	14,301	16,294
Work-in-process	62,558	58,341
Finished goods	9,420	7,079
Inventory	$ 333,379	$ 269,163

Property, Plant and Equipment_2

Property, Plant and Equipment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Property, plant and equipment
Property, plant, and equipment	$ 356,332		$ 284,747
Less: accumulated depreciation	(31,679)		(29,124)
Property, plant, and equipment, net	324,653		255,623
Capitalized interest	4,300	$ 0
Depreciation expense	2,600	$ 1,600
Land
Property, plant and equipment
Property, plant, and equipment	1,165		1,165
Construction in progress
Property, plant and equipment
Property, plant, and equipment	235,548		169,415
Leasehold Improvements
Property, plant and equipment
Property, plant, and equipment	2,645		2,099
Software, machinery and equipment
Property, plant and equipment
Property, plant, and equipment	$ 116,974		$ 112,068

Intangible Assets and Goodwil_2

Intangible Assets and Goodwill - Gross Carrying Amount (Details) - USD ($) $ in Thousands	Nov. 22, 2021	Mar. 31, 2022	Dec. 31, 2021
Gross carrying amount and accumulated amortization of acquired identifiable intangible assets
Gross Carrying Amount		$ 224,416	$ 165,027
Accumulated Amortization		(12,009)	(6,819)
Total		212,407	158,208
Goodwill		232,031	220,436
Translation loss on goodwill		$ (1,296)
Applied Cryo Technologies
Gross carrying amount and accumulated amortization of acquired identifiable intangible assets
Acquired	$ 70,484
Goodwill	$ 93,251
In process research and development
Gross carrying amount and accumulated amortization of acquired identifiable intangible assets
Gross Carrying Amount			29,000
Total			$ 29,000
Acquired technology
Gross carrying amount and accumulated amortization of acquired identifiable intangible assets
Weighted Average Amortization Period		14 years	13 years
Gross Carrying Amount		$ 104,605	$ 45,530
Accumulated Amortization		(7,121)	(5,392)
Total		$ 97,484	$ 40,138
Dry stack electrolyzer technology
Gross carrying amount and accumulated amortization of acquired identifiable intangible assets
Weighted Average Amortization Period		5 years
Gross Carrying Amount		$ 29,000
Accumulated Amortization		(483)
Total		$ 28,517
Customer relationships, Non-compete agreements, Backlog & Trademark
Gross carrying amount and accumulated amortization of acquired identifiable intangible assets
Weighted Average Amortization Period		12 years	12 years
Gross Carrying Amount		$ 90,811	$ 90,497
Accumulated Amortization		(4,405)	(1,427)
Total		$ 86,406	$ 89,070
Customer Relationships | Applied Cryo Technologies
Gross carrying amount and accumulated amortization of acquired identifiable intangible assets
Weighted Average Amortization Period	15 years
Acquired	$ 26,600

Intangible Assets and Goodwil_3

Intangible Assets and Goodwill - Estimated Amortization Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Intangible Assets and Goodwill
Amortization of Intangible Assets	$ 5,190	$ 364
Estimated amortization expense
Remainder of 2022	18,743
2023	21,189
2024	21,131
2025	20,353
2026	18,797
2027 and thereafter	112,194
Total	$ 212,407

Intangible Assets and Goodwil_4

Intangible Assets and Goodwill - Carrying Amount of Goodwill (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2022USD ($)
Goodwill [Roll Forward]
Goodwill, Beginning Balance	$ 220,436
Acquisitions	12,943
Adjustments	(52)
Loss due to currency translation	(1,296)
Goodwill, Ending Balance	$ 232,031

Long-Term Debt (Details)

Long-Term Debt (Details) - USD ($) $ in Millions	Mar. 31, 2022	Mar. 31, 2019
Term Loan facility
Long-Term Debt
Incremental term loan	$ 99.8
Generate Lending, LLC | Secured term loan facility | Loan and security agreement
Long-Term Debt
Loan Amount		$ 100

Convertible Senior Notes - Conv

Convertible Senior Notes - Conversion (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Jan. 31, 2021	Dec. 31, 2020	May 31, 2020	May 29, 2020	May 18, 2020	Mar. 31, 2018
Convertible Senior Notes
Net proceeds	$ 17,273	$ 10,661
Conversion of convertible senior notes to common stock		$ 15,345
5.5% Convertible Senior Notes
Convertible Senior Notes
Principal amount			$ 160	$ 33,500				$ 100,000
Interest rate (as a percent)		5.50%	5.50%	5.50%	5.50%			5.50%
3.75% Convertible Senior Notes
Convertible Senior Notes
Principal amount	$ 197,278	$ 15,200			$ 212,500	$ 12,500	$ 200,000
Interest rate (as a percent)	3.75%	3.75%			3.75%	3.75%	3.75%
Conversion of convertible senior notes to common stock	$ 0

Convertible Senior Notes (Detai

Convertible Senior Notes (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021	Jan. 31, 2021	Dec. 31, 2020	May 31, 2020	May 29, 2020	May 18, 2020	Mar. 31, 2018
Convertible Senior Notes
Net carrying amount	$ 192,949	$ 192,633
3.75% Convertible Senior Notes
Convertible Senior Notes
Principal amount	197,278		$ 15,200			$ 212,500	$ 12,500	$ 200,000
Unamortized debt issuance costs	(4,329)
Net carrying amount	$ 192,949
5.5% Convertible Senior Notes
Convertible Senior Notes
Principal amount				$ 160	$ 33,500				$ 100,000

Convertible Senior Notes - Expe

Convertible Senior Notes - Expenses and Interest (Details) - 3.75% Convertible Senior Notes - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Debt Instrument [Line Items]
Interest expense	$ 1,849	$ 1,897
Amortization of debt issuance costs	316	1,258
Total	$ 2,165	$ 3,155
Effective interest rate (as a percent)	4.50%	4.50%

Convertible Senior Notes - Capp

Convertible Senior Notes - Capped Call and Common Stock Forward (Details) - USD ($) $ / shares in Units, $ in Thousands	May 18, 2020	Nov. 30, 2020	Aug. 31, 2020	Mar. 31, 2022	Mar. 31, 2021	Jan. 31, 2021	Dec. 31, 2020	May 31, 2020	May 29, 2020	Mar. 31, 2018
Capped Call and Common Stock Forward
Closing stock price on grant date		$ 22.25	$ 10.25
Common stock shares issued		43,700,000	35,276,250
Common Stock Forward
Capped Call and Common Stock Forward
Net cost incurred				$ 27,500
Number of shares settled				0	5,900,000
3.75% Convertible Senior Notes
Capped Call and Common Stock Forward
Interest rate (as a percent)	3.75%			3.75%	3.75%			3.75%	3.75%
Principal amount	$ 200,000			$ 197,278	$ 15,200			$ 212,500	$ 12,500
Closing stock price on grant date				$ 28.61
Convertible senior notes				$ 1,100,000
3.75% Convertible Senior Notes | Capped Call
Capped Call and Common Stock Forward
Capped call options amount	$ 16,200
Cap price	$ 6.7560
Premium (as a percent)	60.00%
Closing stock price on grant date	$ 4.11
5.5% Convertible Senior Notes
Capped Call and Common Stock Forward
Interest rate (as a percent)					5.50%	5.50%	5.50%	5.50%		5.50%
Principal amount						$ 160	$ 33,500			$ 100,000
5.5% Convertible Senior Notes | Common Stock Forward
Capped Call and Common Stock Forward
Common stock shares issued				14,397,906

Stockholders' Equity - Common S

Stockholders' Equity - Common Stock and Warrants (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended			2 Months Ended	3 Months Ended		12 Months Ended
	Feb. 28, 2021	Nov. 30, 2020	Aug. 31, 2020	Feb. 28, 2021	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021	Dec. 31, 2017
Stockholders' equity
Net proceeds from shares of common stock sold		$ 927,300	$ 344,400			$ 3,587,825
Common Stock, Shares, Issued					595,209,356		594,729,610
Common stock, par value (in dollars per share)					$ 0.01		$ 0.01
Common stock shares issued		43,700,000	35,276,250
Share price (in dollars per share)		$ 22.25	$ 10.25
Proceeds from exercise of warrants, net of transaction costs						$ 15,445
SK Holdings Co LTD
Stockholders' equity
Net proceeds from shares of common stock sold	$ 1,600,000
Common stock shares issued	54,966,188
Per share price of shares of common stock	$ 29.2893			$ 29.2893
Public Offerings
Stockholders' equity
Net proceeds from shares of common stock sold				$ 2,000,000
Common stock shares issued				32,200,000
Share price (in dollars per share)	$ 65			$ 65
Warrant Issued With Amazon And Walmart Stores Inc Transaction Agreement In 2017
Stockholders' equity
Number of warrants exercised (in shares)					75,655,478		75,655,478
Maximum | Warrant Issued With Amazon And Walmart Stores Inc Transaction Agreement In 2017
Stockholders' equity
Class of Warrant or Right Issued								110,573,392

Warrant Transaction Agreements

Warrant Transaction Agreements - Amazon.com, Inc. Transaction Agreement (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021	Apr. 04, 2017
Class of Warrant or Right [Line Items]
Selling, general and administrative	$ 80,890	$ 25,579
Provision for loss contracts related to service	$ 7,297	361
Amazon
Class of Warrant or Right [Line Items]
Number of warrants exercised (in shares)	17,461,994		17,461,994
Warrants issued with the Amazon, Inc transaction agreement
Class of Warrant or Right [Line Items]
Shares of common stock that can be purchased from warrants issued (in shares)				55,286,696
Reduction in revenue	$ 110	$ 104
Number of warrants exercised (in shares)	17,461,994	9,214,449
Warrant shares vested (in shares)			55,286,696

Warrant Transaction Agreement_2

Warrant Transaction Agreements - Walmart Stores, Inc. Transaction Agreement (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021	Jul. 20, 2017
Warrants issued with the Walmart Stores, Inc transaction agreement
Warrant Transaction Agreements
Shares of common stock that can be purchased from warrants issued (in shares)				55,286,696
Reduction in revenue	$ 1.7	$ 1.6
Warrant shares vested (in shares)	20,368,782
Number of warrants exercised (in shares)	0	7,274,565	13,094,217
Amazon
Warrant Transaction Agreements
Number of warrants exercised (in shares)	17,461,994		17,461,994

Revenue - Disaggregation of Rev

Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Revenue
Net revenue	$ 140,804	$ 71,958
Sales of fuel cell systems
Revenue
Net revenue	37,528	26,419
Sale of hydrogen infrastructure
Revenue
Net revenue	27,089	20,353
Sale of electrolyzers
Revenue
Net revenue	4,059
Sale of oil and gas equipment
Revenue
Net revenue	21,968
Services performed on fuel cell systems and related infrastructure
Revenue
Net revenue	8,240	6,045
Power purchase agreements
Revenue
Net revenue	10,037	7,826
Fuel delivered to customers
Revenue
Net revenue	13,429	11,127
Sale of cryogenic equipment
Revenue
Net revenue	18,203
Other
Revenue
Net revenue	$ 251	$ 188

Revenue - Contract balances (De

Revenue - Contract balances (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Revenue
Accounts receivable	$ 57,322	$ 92,675
Contract assets	38,713	38,757
Contract liabilities	$ 155,185	$ 183,090

Revenue - Changes in contract a

Revenue - Changes in contract assets and contract liabilities (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Contract assets
Net change in contract assets	$ 44
Contract liabilities
Increases due to cash received, net of amounts recognized as revenue during the period		$ 13,327	$ 182,052
Contract liabilities assumed as part of acquisition	3,818	35,727
Revenue recognized that was included in the contract liability balance as of the beginning of the period	(45,050)	(110,974)
Net change in contract liabilities	(27,905)	106,805
Sales of fuel cell systems
Contract assets
Transferred to receivables from contract assets recognized at the beginning of the period	(3,693)	(14,638)
Contract assets assumed as part of acquisition		9,960
Revenue recognized and not billed as of the end of the period	3,649	25,246
Net change in contract assets	$ (44)	$ 20,568

Revenue - Estimated future reve

Revenue - Estimated future revenue (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2022USD ($)
Revenue
Total estimated future revenue	$ 682,149
Sales of fuel cell systems
Revenue
Total estimated future revenue	16,466
Sale of hydrogen installations and other infrastructure
Revenue
Total estimated future revenue	40,487
Sale of electrolyzers
Revenue
Total estimated future revenue	51,267
Sale of oil and gas equipment
Revenue
Total estimated future revenue	73,270
Services performed on fuel cell systems and related infrastructure
Revenue
Total estimated future revenue	98,635
Power purchase agreements
Revenue
Total estimated future revenue	255,929
Fuel delivered to customers and related equipment
Revenue
Total estimated future revenue	83,796
Sale of cryogenic equipment
Revenue
Total estimated future revenue	$ 62,299
Maximum | Sales of fuel cell systems
Revenue
Duration of estimated revenue expected to be recognized in future (in years)	1 year
Maximum | Sale of hydrogen installations and other infrastructure
Revenue
Duration of estimated revenue expected to be recognized in future (in years)	1 year
Maximum | Services performed on fuel cell systems and related infrastructure
Revenue
Duration of estimated revenue expected to be recognized in future (in years)	7 years
Maximum | Power purchase agreements
Revenue
Duration of estimated revenue expected to be recognized in future (in years)	7 years
Minimum | Services performed on fuel cell systems and related infrastructure
Revenue
Duration of estimated revenue expected to be recognized in future (in years)	5 years
Minimum | Power purchase agreements
Revenue
Duration of estimated revenue expected to be recognized in future (in years)	5 years

Revenue - Others (Details)

Revenue - Others (Details) - USD ($) $ in Millions	Mar. 31, 2022	Mar. 31, 2021
Revenue
Capitalized contract costs	$ 0.5	$ 1.7

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Income Taxes
Income tax benefit	$ 414	$ 0

Fair Value Measurements - Narra

Fair Value Measurements - Narrative (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2022USD ($)
Fair Value Measurements
Assets, transfers from level 1 to level 2	$ 0
Assets, transfers from level 2 to level 1	0
Asset transfer into Level 3	0
Asset transfer out of Level 3	0
Liabilities, transfers from level 1 to level 2	0
Liabilities, transfers from level 2 to level 1	0
Liabilities transfer into Level 3	0
Liabilities transfer out of Level 3	0
Payments to acquire equity method investments	$ 22,600

Fair Value Measurements - Asset

Fair Value Measurements - Assets and liabilities measured at fair value on a recurring basis (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Fair Value
Assets, Carrying Amount	$ 5,803,805	$ 5,950,076
Liabilities, Carrying amount	1,327,573	1,344,380
Contingent consideration
Fair Value
Liabilities, Carrying amount		62,297
Liabilities, Fair value		62,297
Swaps and Forward Contracts
Fair Value
Liabilities, Carrying amount		981
Liabilities, Fair value		981
Cash and cash equivalents
Fair Value
Assets, Carrying Amount		115,241
Assets, Fair Value		115,241
Corporate bonds
Fair Value
Assets, Carrying Amount		226,382
Assets, Fair Value		226,382
U.S. Treasuries
Fair Value
Assets, Carrying Amount		1,013,883
Assets, Fair Value		1,013,883
Equity securities
Fair Value
Assets, Carrying Amount		147,995
Assets, Fair Value		147,995
Swaps and Forward Contracts
Fair Value
Assets, Carrying Amount		70
Assets, Fair Value		$ 70
Recurring basis | Level 1 | Swaps and Forward Contracts
Fair Value
Liabilities, Fair value	1,165
Recurring basis | Level 1 | Cash and cash equivalents
Fair Value
Assets, Fair Value	37,116
Recurring basis | Level 1 | U.S. Treasuries
Fair Value
Assets, Fair Value	554,307
Recurring basis | Level 1 | Equity securities
Fair Value
Assets, Fair Value	147,826
Recurring basis | Level 2 | Corporate bonds
Fair Value
Assets, Fair Value	244,921
Recurring basis | Level 3 | Contingent consideration
Fair Value
Liabilities, Fair value	103,219
Carrying value | Recurring basis | Contingent consideration
Fair Value
Liabilities, Carrying amount	103,219
Carrying value | Recurring basis | Swaps and Forward Contracts
Fair Value
Liabilities, Carrying amount	371
Carrying value | Recurring basis | Cash and cash equivalents
Fair Value
Assets, Carrying Amount	37,116
Carrying value | Recurring basis | Corporate bonds
Fair Value
Assets, Carrying Amount	244,921
Carrying value | Recurring basis | U.S. Treasuries
Fair Value
Assets, Carrying Amount	554,307
Carrying value | Recurring basis | Equity securities
Fair Value
Assets, Carrying Amount	147,826
Fair value | Recurring basis | Contingent consideration
Fair Value
Liabilities, Fair value	103,219
Fair value | Recurring basis | Swaps and Forward Contracts
Fair Value
Liabilities, Fair value	(1,165)
Fair value | Recurring basis | Cash and cash equivalents
Fair Value
Assets, Fair Value	37,116
Fair value | Recurring basis | Corporate bonds
Fair Value
Assets, Fair Value	244,921
Fair value | Recurring basis | U.S. Treasuries
Fair Value
Assets, Fair Value	554,307
Fair value | Recurring basis | Equity securities
Fair Value
Assets, Fair Value	$ 147,826

Fair Value Measurements - Ass_2

Fair Value Measurements - Assets and liabilities measured at fair value on recurring basis that have unobservable inputs (Details) - Recurring basis - Level 3 $ in Thousands	Mar. 31, 2022USD ($)
Scenario based method | Credit spread | Business Combination, One | Minimum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Contingent Consideration, measurement input	12.34
Scenario based method | Credit spread | Business Combination, One | Maximum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Contingent Consideration, measurement input	13.77
Scenario based method | Credit spread | Business Combination, One | Weighted Average
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Contingent Consideration, measurement input	13.06
Scenario based method | Discount rate | Business Combination, One | Minimum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Contingent Consideration, measurement input	13.84
Scenario based method | Discount rate | Business Combination, One | Maximum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Contingent Consideration, measurement input	16.06
Scenario based method | Discount rate | Business Combination, One | Weighted Average
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Contingent Consideration, measurement input	14.95
Monte carlo simulation | Credit spread | Business Combination, Two
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Contingent Consideration, measurement input	12.50
Monte carlo simulation | Credit spread | Business Combination, Three | Minimum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Contingent Consideration, measurement input	13
Monte carlo simulation | Credit spread | Business Combination, Three | Maximum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Contingent Consideration, measurement input	13.08
Monte carlo simulation | Credit spread | Business Combination, Three | Weighted Average
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Contingent Consideration, measurement input	12.92
Monte carlo simulation | Discount rate | Business Combination, Two
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Contingent Consideration, measurement input	14.63
Monte carlo simulation | Revenue volatility | Business Combination, Two
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Contingent Consideration, measurement input	57.24
Monte carlo simulation | Revenue volatility | Business Combination, Two | Weighted Average
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Contingent Consideration, measurement input	35
Monte carlo simulation | Revenue volatility | Business Combination, Three
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Contingent Consideration, measurement input	35
Monte carlo simulation | Revenue volatility | Business Combination, Three | Minimum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Contingent Consideration, measurement input	25.9
Monte carlo simulation | Revenue volatility | Business Combination, Three | Maximum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Contingent Consideration, measurement input	47.7
Monte carlo simulation | Gross profit volatility | Business Combination, Three | Minimum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Contingent Consideration, measurement input	24.2
Monte carlo simulation | Gross profit volatility | Business Combination, Three | Maximum
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Contingent Consideration, measurement input	113.9
Monte carlo simulation | Gross profit volatility | Business Combination, Three | Weighted Average
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Contingent Consideration, measurement input	70
Fair value
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Contingent Consideration	$ 103,219
Fair value | Scenario based method | Business Combination, One
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Contingent Consideration	89,670
Fair value | Monte carlo simulation | Business Combination, Two
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Contingent Consideration	10,400
Fair value | Monte carlo simulation | Business Combination, Three
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Contingent Consideration	$ 3,149

Fair Value Measurements - Level

Fair Value Measurements - Level 3 Instruments Reconciliation (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2022USD ($)
Reconciliations of the beginning and ending balances for liabilities measured at fair value on a recurring basis using significant unobservable inputs (i.e. Level 3)
Balance at the beginning of the period	$ 62,297
Payments	(2,667)
Additions due to acquisitions	41,732
Fair value adjustments	2,461
Gain due to currency translation	(604)
Balance at the end of the period	$ 103,219

Investments - Available-for-sal

Investments - Available-for-sale securities (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 816,976	$ 1,242,933
Gross Unrealized Gains		20
Gross Unrealized Losses	(17,748)	(2,688)
Fair Value	799,228	1,240,265
Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	251,827	228,614
Gross Unrealized Losses	(6,906)	(2,232)
Fair Value	244,921	226,382
U.S. Treasuries
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	565,149	1,014,319
Gross Unrealized Gains		20
Gross Unrealized Losses	(10,842)	(456)
Fair Value	$ 554,307	$ 1,013,883

Investments - Equity Securities

Investments - Equity Securities (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Debt and Equity Securities, FV-NI [Line Items]
Cost	$ 146,247	$ 141,257
Gross Unrealized Gains	3,351	7,312
Gross Unrealized Losses	(1,772)	(574)
Fair Value	147,826	147,995
Fixed income mutual funds
Debt and Equity Securities, FV-NI [Line Items]
Cost	70,247	70,247
Gross Unrealized Losses	(1,772)	(574)
Fair Value	68,475	69,673
Exchange traded mutual funds
Debt and Equity Securities, FV-NI [Line Items]
Cost	76,000	71,010
Gross Unrealized Gains	3,351	7,312
Fair Value	$ 79,351	$ 78,322

Investments - Contractual Matur

Investments - Contractual Maturity (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Amortized Cost
Within one year	$ 307,565	$ 670,584
After one through five years	509,411	572,349
Amortized Cost	816,976	1,242,933
Fair Value
Within one year	305,681	670,306
After one through five years	493,547	569,959
Fair Value	799,228	1,240,265
Accrued interest income	$ 3,300	$ 3,700

Operating and Finance Lease L_3

Operating and Finance Lease Liabilities - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Lessee, Lease, Description [Line Items]
Rental expense for all operating lease	$ 14,000	$ 8,000
Right of use assets, finance lease	42,300		$ 33,900
Amortization of right-of-use asset from finance lease	2,200		1,500
Prepaid rent and security deposit	3,800		$ 3,500
Amortization of right of use asset, finance Lease	749
Interest on lease liabilities, finance lease	$ 556
Minimum
Lessee, Lease, Description [Line Items]
Lease Term - as Lessee	1 year
Maximum
Lessee, Lease, Description [Line Items]
Lease Term - as Lessee	9 years

Operating and Finance Lease L_4

Operating and Finance Lease Liabilities - Future minimum lease payments under operating and finance leases (Details) $ in Thousands	Mar. 31, 2022USD ($)
Future minimum lease payments under operating lease
Remainder of 2022	$ 42,373
2023	56,034
2024	54,667
2025	50,800
2026	43,515
2027 and thereafter	43,652
Total future minimum lease payments	291,041
Less imputed interest	(71,350)
Total operating lease, liabilities	219,691
Future minimum lease payments under finance leases
Remainder of 2022	5,929
2023	7,800
2024	7,773
2025	10,671
2026	8,039
2027 and thereafter	2,343
Total future minimum lease payments	42,555
Less imputed interest	(6,381)
Total finance lease liabilities	36,174
Future minimum lease payments under operating and finance leases
Remainder of 2022	48,302
2023	63,834
2024	62,440
2025	61,471
2026	51,554
2027 and thereafter	45,995
Total future minimum payments	333,596
Less imputed interest	(77,731)
Total	$ 255,865

Operating and Finance Lease L_5

Operating and Finance Lease Liabilities - Other information related to the operating leases (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Lessee, Operating Lease, Description [Abstract]
Cash payments	$ 13,547	$ 6,734
Weighted average remaining lease term (in years)	5 years 5 months 15 days	5 years 9 months 7 days
Weighted average discount rate (as a percent)	10.90%	11.60%

Operating and Finance Lease L_6

Operating and Finance Lease Liabilities - Other information related to the finance leases (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Other information
Cash payments	$ 1,868	$ 433
Weighted average remaining lease term (years)	4 years 5 months 8 days	5 years 1 month 6 days
Weighted average discount rate	6.50%	7.20%

Finance Obligation - Narrative

Finance Obligation - Narrative (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Sale Leaseback Transaction [Line Items]
Total finance lease liabilities	$ 36,174
Short term finance lease obligation	5,654	$ 4,718
Long term finance lease obligation	30,520	24,611
Sale Leaseback Agreements
Sale Leaseback Transaction [Line Items]
Total finance lease liabilities	16,130	17,000
Short term finance lease obligation	3,800	4,500
Long term finance lease obligation	12,300	12,500
Sale Leaseback Agreements | Future Services [Member]
Sale Leaseback Transaction [Line Items]
Total finance lease liabilities	244,100	236,600
Short term finance lease obligation	40,500	37,500
Long term finance lease obligation	$ 203,600	$ 199,100

Finance Obligation - Future min

Finance Obligation - Future minimum payments under finance obligations (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Future minimum lease payments under finance leases
Remainder of 2022	$ 5,929
2023	7,800
2024	7,773
2025	10,671
2026	8,039
2027 and thereafter	2,343
Total future minimum lease payments	42,555
Less imputed interest	(6,381)
Total finance lease liabilities	36,174
Finance obligation
Future minimum lease payments under finance leases
Remainder of 2022	52,775
2023	69,122
2024	74,877
2025	60,717
2026	43,994
2027 and thereafter	35,008
Total future minimum lease payments	336,493
Less imputed interest	(76,269)
Total finance lease liabilities	260,224
Sale of Future Revenue - Debt
Future minimum lease payments under finance leases
Remainder of 2022	49,193
2023	65,591
2024	65,591
2025	60,334
2026	43,611
2027 and thereafter	34,452
Total future minimum lease payments	318,772
Less imputed interest	(74,678)
Total finance lease liabilities	244,094
Sale Leaseback Agreements
Future minimum lease payments under finance leases
Remainder of 2022	3,582
2023	3,531
2024	9,286
2025	383
2026	383
2027 and thereafter	556
Total future minimum lease payments	17,721
Less imputed interest	(1,591)
Total finance lease liabilities	$ 16,130	$ 17,000

Finance Obligation - Other info

Finance Obligation - Other information related to finance obligations (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Sale Leaseback Transaction [Line Items]
Cash payments	$ 1,868	$ 433
Weighted average remaining term (years)	4 years 5 months 8 days	5 years 1 month 6 days
Weighted average discount rate	6.50%	7.20%
Finance obligation
Sale Leaseback Transaction [Line Items]
Cash payments	$ 17,409	$ 12,816
Weighted average remaining term (years)	4 years 10 months 28 days	4 years 10 months 24 days
Weighted average discount rate	10.80%	11.20%

Commitments and Contingencies -

Commitments and Contingencies - Concentrations of Credit Risk (Details) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2022USD ($)customer	Mar. 31, 2021USD ($)customer	Dec. 31, 2021USD ($)customer
Customer Concentration
Federal depository insurance coverage	$ 250
Restricted cash	252,600		$ 275,100
Letter of credit	339,700		286,000
Construction escrow	67,700		$ 67,700
Consideration held by paying agent.	5,000
Consolidated revenue	140,804	$ 71,958
Collateral Related to Acquisitions | Frames Holding B.V.
Customer Concentration
Restricted Cash	15,300
Restricted Cash	$ 15,300
Accounts receivable | Customer concentration | Customers
Customer Concentration
Number of customers | customer	2		1
Concentration risk (as a percent)	30.00%		46.60%
Revenues | Customer concentration | Customers
Customer Concentration
Number of customers | customer	5	3
Concentration risk (as a percent)	67.00%	71.20%
Warrants issued with the Amazon, Inc transaction agreement
Customer Concentration
Reduction in revenue	$ 110	$ 104

Employee Benefit Plans - Assump

Employee Benefit Plans - Assumptions For Estimating Fair Value (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Nov. 30, 2020	Aug. 31, 2020
Assumptions for estimating fair value
Closing stock price on grant date			$ 22.25	$ 10.25
Service Options Awards
Employee Benefit Plans
Compensation cost	$ 5.9	$ 3.3
Options granted	451,500
Performance Option Awards
Employee Benefit Plans
Compensation cost	$ 25.1	0
Options granted	0
Stock Incentive Plan 2011 And 2021
Employee Benefit Plans
Compensation cost	$ 40.8	$ 8.5

Employee Benefit Plans - Stock

Employee Benefit Plans - Stock Activity, Weighted Average Exercise Price (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Stock option activity additional disclosures
Period for recognition	2 years 1 month 6 days
Service Options Awards
Shares
Options outstanding, beginning balance (in shares)	9,786,909
Granted (in shares)	451,500
Exercised (in shares)	(56,692)
Forfeited (in shares)	(16,717)
Options outstanding, end balance (in shares)	10,165,000		9,786,909
Options exercisable (in shares)	4,900,538
Options unvested (in shares)	5,264,462
Weighted Average Exercise Price
Options outstanding, beginning balance, weighted-average exercise price	$ 11.65
Granted, weighted-average exercise price	23.83
Exercised, weighted-average exercise price	5.13
Forfeited, weighted-average exercise price	13.16
Options outstanding, end balance, weighted-average exercise price	12.20		$ 11.65
Options exercisable, weighted-average exercise price	5.96
Options unvested, weighted-average exercise price	$ 18.03
Stock option activity additional disclosures
Options outstanding, weighted-average remaining contractual term	7 years 6 months		7 years 8 months 12 days
Options exercisable, weighted-average remaining contractual term	6 years 3 months 18 days
Options unvested, weighted-average remaining contractual term	8 years 8 months 12 days
Options outstanding, aggregate intrinsic value	$ 176,301		$ 172,412
Options exercisable, aggregate intrinsic value	114,080
Options unvested, aggregate intrinsic value	$ 62,221
Weighted-average grant date fair value of options granted (per share)	$ 15.34	$ 31.78
Fair value of stock options that vested during the period	$ 5,600	$ 2,900
Compensation cost	5,900	3,300
Unrecognized compensation cost	$ 47,000	$ 40,500
Period for recognition	2 years 1 month 17 days	2 years 1 month 17 days
Intrinsic fair value of options exercised	$ 1,100	$ 1,000
Performance Option Awards
Shares
Granted (in shares)	0
Stock option activity additional disclosures
Compensation cost	$ 25,100	$ 0
Unrecognized compensation cost	$ 125,100
Period for recognition	2 years 5 months 23 days

Employee Benefit Plans - Restri

Employee Benefit Plans - Restricted Stock Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Employee Benefit Plans
Period for recognition	2 years 1 month 6 days
Restricted stock outstanding
Employee Benefit Plans
Compensation cost	$ 9,800	$ 5,200
Unrecognized compensation cost	83,700	64,100
Weighted average grant-date fair value of the restricted stock units granted	3,900	457
Fair value of restricted stock units vested	$ 23,860	$ 43,890
Shares
Unvested restricted stock, beginning balance (in shares)	4,851,873
Granted (in shares)	802,500
Vested (in shares)	(196,832)
Forfeited (in shares)	(18,334)
Unvested restricted stock, end balance (in shares)	5,439,207
Weighted Average Grant Date Fair Value
Unvested restricted stock, beginning balance, weighted average grant date fair value	$ 21.59
Granted, weighted average grant date fair value	23.86
Vested, weighted average grant date fair value	41.93
Forfeited, weighted average grant date fair value	13.20
Unvested restricted stock, end balance, weighted average grant date fair value	$ 18.31
Aggregate Intrinsic Value
Unvested restricted stock, end balance, aggregate intrinsic value	$ 155,616

Employee Benefit Plans - 401(K)

Employee Benefit Plans - 401(K) Saving And Retirement Plan (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Non Employee Director
Non-Employee Benefit Plan Compensation
Granted (in shares)	3,290	2,653
Compensation cost	$ 94	$ 85
Savings And Retirement Plan 401 K
401(K) Savings & Retirement Plan
Common stock, shares issued	96,539	12,513
Total expense (including issuance of shares)	$ 2,200	$ 1,300

Segment Reporting (Details)

Segment Reporting (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2022USD ($)segment	Mar. 31, 2021USD ($)	Dec. 31, 2021USD ($)
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 140,804	$ 71,958
Long-Lived Assets	$ 671,788		$ 573,556
Number of operating segments | segment	1
Number of reportable segments | segment	1
North America
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 113,678	69,646
Long-Lived Assets	665,992		570,778
Other Member
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	27,126	$ 2,312
Long-Lived Assets	$ 5,796		$ 2,778