Archer Aviation (ACHR) 10-K29 Feb 242023 FY Annual reportFinancial data

Company Profile

Cover

Cover - USD ($) $ in Millions	12 Months Ended
Cover - USD ($) $ in Millions	Dec. 31, 2023	Feb. 23, 2024	Jun. 30, 2023
Entity Information [Line Items]
Document Type	10-K
Document Quarterly Report	true
Current Fiscal Year End Date	--12-31
Document Period End Date	Dec. 31, 2023
Document Transition Report	false
Entity File Number	001-39668
Entity Registrant Name	Archer Aviation Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	85-2730902
Entity Address, Address Line One	190 West Tasman Drive
Entity Address, City or Town	San Jose
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	95134
City Area Code	650
Local Phone Number	272-3233
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Document Financial Statement Error Correction	false
Entity Shell Company	false
Entity Public Float			$ 839.9
Documents Incorporated by Reference	Part III of this Form 10-K (the “Annual Report”) incorporates by reference certain information from the Registrant's Definitive Proxy Statement (“Proxy Statement”) relating to the 2024 Annual Meeting of Stockholders or an amendment to this report under cover of Form 10-K/A to be filed within 120 days of the end of its fiscal year ended December 31, 2023.
Entity Central Index Key	0001824502
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	FY
Amendment Flag	false
Class A
Entity Information [Line Items]
Title of 12(b) Security	Class A common stock, par value $0.0001 per share
Trading Symbol	ACHR
Security Exchange Name	NYSE
Entity Common Stock, Shares Outstanding		272,319,871
Warrants
Entity Information [Line Items]
Title of 12(b) Security	Warrants, each whole warrant exercisable for one share of Class A common stock at an exercise price of $11.50 per share
Trading Symbol	ACHR WS
Security Exchange Name	NYSE
Class B
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		38,254,915

Audit Information

Audit Information	12 Months Ended
Audit Information	Dec. 31, 2023
Audit Information [Abstract]
Auditor Name	PricewaterhouseCoopers LLP
Auditor Firm ID	238
Auditor Location	Irvine, California

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Current assets
Cash and cash equivalents	$ 464.6	$ 69.4
Restricted cash	6.9	2.9
Short-term investments:	0	461.8
Prepaid expenses	7.9	9.8
Other current assets	0.8	1.6
Total current assets	480.2	545.5
Property and equipment, net	57.6	11.5
Intangible assets, net	0.4	0.4
Right-of-use assets	8.9	11.9
Other long-term assets	7.2	4.5
Total assets	554.3	573.8
Current liabilities
Accounts payable	14.3	3.6
Current portion of lease liabilities	2.8	3.7
Current portion of notes payable	0	9.3
Accrued expenses and other current liabilities	96.9	36.7
Total current liabilities	114	53.3
Notes payable, net of current portion	7.2	0
Lease liabilities, net of current portion	13.2	9.2
Warrant liabilities	39.9	7
Other long-term liabilities	12.9	11
Total liabilities	187.2	80.5
Commitments and contingencies (Note 8)
Stockholders’ equity
Preferred stock, $0.0001 par value; 10,000,000 shares authorized; no shares issued and outstanding as of December 31, 2023 and 2022	0	0
Additional paid-in capital	1,515.9	1,185
Accumulated deficit	(1,148.8)	(690.9)
Accumulated other comprehensive loss	0	(0.8)
Total stockholders’ equity	367.1	493.3
Total liabilities and stockholders’ equity	554.3	573.8
Class A
Stockholders’ equity
Common stock, value, issued	0	0
Class B
Stockholders’ equity
Common stock, value, issued	$ 0	$ 0

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2023	Dec. 31, 2022
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, authorized (in shares)	10,000,000	10,000,000
Preferred stock, issued (in shares)	0	0
Preferred stock, outstanding (in shares)	0	0
Class A
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, authorized (in shares)	700,000,000	700,000,000
Common stock, issued (in shares)	265,617,341	177,900,738
Common stock, outstanding (in shares)	265,617,341	177,900,738
Class B
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, authorized (in shares)	300,000,000	300,000,000
Common stock, issued (in shares)	38,165,615	63,738,197
Common stock, outstanding (in shares)	38,165,615	63,738,197

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Operating expenses
Research and development	$ 276,400	$ 171,500	$ 64,300
General and administrative	168,400	165,100	176,700
Other warrant expense	2,100	10,800	117,300
Total operating expenses	446,900	347,400	358,300
Loss from operations	(446,900)	(347,400)	(358,300)
Gain on forgiveness of PPP loan	0	0	900
Other (expense) income, net	(26,900)	27,800	10,600
Interest income (expense), net	16,400	2,300	(1,000)
Loss before income taxes	(457,400)	(317,300)	(347,800)
Income tax expense	(500)	0	0
Net loss	$ (457,900)	$ (317,300)	$ (347,800)
Net loss per share, basic (in dollars per share)	$ (1.69)	$ (1.32)	$ (3.14)
Net loss per share, diluted (in dollars per share)	$ (1.69)	$ (1.32)	$ (3.14)
Weighted-average common shares, basic (in shares)	270,408,132	240,476,894	110,836,238
Weighted-average common shares, diluted (in shares)	270,408,132	240,476,894	110,836,238

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Loss - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Statement of Comprehensive Income [Abstract]
Net loss	$ (457.9)	$ (317.3)	$ (347.8)
Other comprehensive income (loss):
Unrealized gain (loss) on available-for-sale securities, net of tax	0.8	(0.8)	0
Comprehensive loss	$ (457.1)	$ (318.1)	$ (347.8)

Consolidated Statements of Stoc

Consolidated Statements of Stockholders’ Equity - USD ($) $ in Millions	Total	Common Stock Class A	Common Stock Class B	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Loss
Beginning balance (in shares) at Dec. 31, 2020		49,828,517	66,714,287
Beginning balance at Dec. 31, 2020	$ 35.9	$ 0	$ 0	$ 61.7	$ (25.8)	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversion of Class B common stock to Class A common stock (in shares)		5,337,446	(5,337,446)
Issuance of restricted stock and restricted stock expense (in shares)		20,833	10,004,612
Issuance of restricted stock and restricted stock expense	118.1			118.1
Exercise of stock options (in shares)		859,544	3,556,492
Exercise of stock options	0.5			0.5
Issuance of warrants and warrant expense	124.3			124.3
Exercise of warrants (in shares)		8,845,058
Exercise of warrants	0.1			0.1
Issuance of Class A common stock pursuant to the Business Combination Agreement (in shares)		36,385,693
Issuance of Class A common stock pursuant to the Business Combination Agreement	162.3			162.3
PIPE financing (in shares)		61,512,500
PIPE financing	600			600
Stock-based compensation	5.5			5.5
Net loss	(347.8)				(347.8)
Other comprehensive income (loss)	0
Ending balance (in shares) at Dec. 31, 2021		162,789,591	74,937,945
Ending balance at Dec. 31, 2021	698.9	$ 0	$ 0	1,072.5	(373.6)	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversion of Class B common stock to Class A common stock (in shares)		8,406,170	(8,406,170)
Issuance of restricted stock and restricted stock expense (in shares)		5,269,553
Issuance of restricted stock and restricted stock expense	71.3			71.3
Exercise of stock options (in shares)		1,435,424	2,208,728
Exercise of stock options	0.4			0.4
Issuance of warrants and warrant expense	14.1			14.1
Cancellation of Class B common stock (Note 10) (in shares)			(5,002,306)
Stock-based compensation	26.7			26.7
Net loss	(317.3)				(317.3)
Other comprehensive income (loss)	(0.8)					(0.8)
Ending balance (in shares) at Dec. 31, 2022		177,900,738	63,738,197
Ending balance at Dec. 31, 2022	493.3	$ 0	$ 0	1,185	(690.9)	(0.8)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversion of Class B common stock to Class A common stock (in shares)		26,449,869	(26,449,869)
Issuance of restricted stock and restricted stock expense (in shares)		7,405,542	0
Issuance of restricted stock and restricted stock expense	(6.6)			(6.6)
Exercise of stock options (in shares)		1,149,934	877,287
Exercise of stock options	0.2			0.2
Issuance of warrants and warrant expense	46			46
Exercise of warrants (in shares)		2,942,778
Exercise of warrants	0			0
Common stock withheld related to net share settlement of equity awards (in shares)		(1,378,367)
Common stock withheld related to net share settlement of equity awards	(3.5)			(3.5)
Common stock issued under employee stock purchase plan (in shares)		1,228,632
Common stock issued under employee stock purchase plan	2.9			2.9
Issuance of Class A common stock pursuant to the Business Combination Agreement (in shares)		1,985,559
Issuance of Class A common stock pursuant to the Business Combination Agreement	11.6			11.6
Common stock issued under stock purchase agreement (in shares)		18,650,273
Common stock issued under stock purchase agreement	89.6			89.6
Common stock issued under at-the-market offering	19.5			19.5
PIPE financing (in shares)		26,173,286
PIPE financing	139			139
Stock-based compensation	32.2			32.2
Net loss	(457.9)				(457.9)
Other comprehensive income (loss)	0.8					0.8
Ending balance (in shares) at Dec. 31, 2023		265,617,341	38,165,615
Ending balance at Dec. 31, 2023	$ 367.1	$ 0	$ 0	$ 1,515.9	$ (1,148.8)	$ 0

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Cash flows from operating activities
Net loss	$ (457.9)	$ (317.3)	$ (347.8)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation, amortization and other	6.5	4.4	1.3
Debt discount and issuance cost amortization	0.7	0.5	0.2
Stock-based compensation	45.2	102.8	123.6
Change in fair value of warrant liabilities and other warrant costs	32.9	(22.9)	(10.4)
Gain on issuance of common stock	(3.6)	0	0
Non-cash lease expense	3.8	4.6	1.7
Research and development warrant expense	17.5	2.9	7
Other warrant expense	2.1	10.8	117.3
Technology and dispute resolution agreements expense	70.3	0	0
Interest income on short-term investments	0	(0.5)	0
Accretion and amortization income of short-term investments	(2.3)	(4.9)	0
Gain on forgiveness of PPP loan	0	0	(0.9)
Changes in operating assets and liabilities:
Prepaid expenses	1.9	(2.2)	(6.8)
Other current assets	0.8	(1.2)	(0.3)
Other long-term assets	(5)	0.4	(2.7)
Accounts payable	9.2	(0.1)	(0.8)
Accrued expenses and other current liabilities	2.3	15.6	12.1
Operating lease right-of-use assets and lease liabilities, net	2.4	(3.4)	(1.9)
Other long-term liabilities	1.6	10.1	0
Net cash used in operating activities	(271.6)	(200.4)	(108.4)
Cash flows from investing activities
Purchase of short-term investments	0	(487.4)	0
Proceeds from maturities of short-term investments	465	30	0
Purchase of property and equipment	(44.3)	(6.9)	(3.5)
Net cash provided by (used in) investing activities	420.7	(464.3)	(3.5)
Cash flows from financing activities
Proceeds from issuance of debt	7.5	0	20
Repayment of long-term debt	(10)	(10)	0
Payment of debt issuance costs	(0.3)	0	(0.2)
Payments for taxes related to net share settlement of equity awards	(3.5)	0	0
Proceeds from PIPE financing	145	0	600
Payment of offering costs in connection with PIPE financing	(6)	0	0
Proceeds from shares issued under at-the-market offering	20.7	0	0
Payment of offering costs in connection with at-the-market offering	(1.2)	0	0
Recapitalization transaction	0	0	257.6
Recapitalization transaction costs	0	0	(55.8)
Proceeds from exercise of stock options	0	0.1	0.5
Proceeds from exercise of stock warrants	0	0	0.1
Proceeds from shares issued under employee stock purchase plan	2.9	0	0
Proceeds from issuance of common stock	95	0	0
Net cash provided by (used in) financing activities	250.1	(9.9)	822.2
Net increase (decrease) in cash, cash equivalents, and restricted cash	399.2	(674.6)	710.3
Cash, cash equivalents, and restricted cash, beginning of period	72.3	746.9	36.6
Cash, cash equivalents, and restricted cash, end of period	471.5	72.3	746.9
Supplemental Cash Flow Information:
Cash paid for interest	0.8	1.5	0.7
Non-cash investing and financing activities:
Purchases of property and equipment included in accounts payable and accrued expenses	10.8	3.1	2.1
Allocation of debt proceeds to stock warrants	0	0	1.2
Conversion of convertible preferred stock to common stock in connection with the reverse recapitalization	0	0	61.5
PIPE financing issuance costs settled with the issuance of Class A common stock	0	0	7
Recapitalization transaction costs settled with the issuance of Class A common stock	$ 0	$ 0	$ 8.1

Organization and Nature of Busi

Organization and Nature of Business	12 Months Ended
Organization and Nature of Business	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Nature of Business	Organization and Nature of Business Organization and Nature of Business Archer Aviation Inc. (the “Company”), a Delaware corporation, with its headquarters located in San Jose, California, is an aerospace company. The Company is designing and developing electric vertical takeoff and landing (“eVTOL”) aircraft for use in urban air mobility (“UAM”) networks. The Company’s mission is to unlock the skies, freeing everyone to reimagine how they move and spend time. The Company’s Planned Lines of Business Upon receipt of all necessary Federal Aviation Administration (“FAA”) certifications and any other government approvals necessary for the Company to manufacture and operate its aircraft, the Company intends to operate two complementary lines of business. The Company’s core focus is direct-to-consumer offerings (“Archer UAM”) with its secondary focus being business-to-business offerings (“Archer Direct”). Archer UAM The Company plans to operate its own UAM ecosystem initially in select major cities. The Company’s UAM ecosystem will operate using its eVTOL aircraft which is currently in development. Archer Direct The Company also plans to selectively sell a certain amount of its eVTOL aircraft along with ancillary products and services to third parties. Business Combination On September 16, 2021 (the “Closing Date”), Archer Aviation, Inc., a Delaware corporation (prior to the closing of the Business Combination (as defined below), “Legacy Archer”), Atlas Crest Investment Corp., a Delaware corporation (“Atlas”), and Artemis Acquisition Sub Inc., a Delaware corporation and a direct, wholly-owned subsidiary of Atlas (“Merger Sub”), consummated the closing of the transactions contemplated by the Business Combination Agreement, dated February 10, 2021, as amended and restated on July 29, 2021, by and among Atlas, Legacy Archer and Merger Sub (the “Business Combination Agreement”), following approval at a special meeting of the stockholders of Atlas held on September 14, 2021 (the “Special Meeting”). Unless otherwise specified or unless the context otherwise requires, references in these notes to Legacy Archer refer to Archer prior to the Business Combination and references in these notes to “New Archer” refer to Archer following the Business Combination. Pursuant to the terms of the Business Combination Agreement, a business combination of Legacy Archer and Atlas was effected by the merger of Merger Sub with and into Legacy Archer, with Legacy Archer surviving the merger (the “Surviving Entity”) as a wholly-owned subsidiary of Atlas (the “Merger,” and, collectively with the other transactions described in the Business Combination Agreement, the “Business Combination”). Following the consummation of the Merger on the Closing Date, the Surviving Entity changed its name from Archer Aviation, Inc. to Archer Aviation Operating Corp., and Atlas changed its name from Atlas Crest Investment Corp. to Archer Aviation Inc. and it became the successor registrant with the U.S. Securities and Exchange Commission (the “SEC”). Prior to the closing of the Business Combination, the Class A common stock and public warrants of Atlas were listed on the New York Stock Exchange (“NYSE”) under the symbols “ACIC” and “ACIC WS,” respectively. New Archer Class A common stock and public warrants are currently listed on the NYSE under the symbols “ACHR” and “ACHR WS,” respectively. The financial statements included in this report reflect (i) the historical operating results of Legacy Archer prior to the Business Combination; (ii) the combined results of Atlas and Legacy Archer following the closing of the Business Combination; (iii) the assets and liabilities of Legacy Archer at their historical cost; and (iv) the Company’s equity structure for all periods presented.

Liquidity and Going Concern

Liquidity and Going Concern	12 Months Ended
Liquidity and Going Concern	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Liquidity and Going Concern	Liquidity and Going Concern Since the Company’s formation, the Company has devoted substantial effort and capital resources to the design and development of its planned eVTOL aircraft and UAM network. Funding of these activities has primarily been through the net proceeds received from the issuance of related and third-party debt (Note 7 - Notes Payable), and the sale of preferred and common stock to related and third parties (Note 9 - Preferred and Common Stock). Through December 31, 2023, the Company has incurred cumulative losses from operations, negative cash flows from operating activities, and has an accumulated deficit of $1,148.8 million. Following the closing of the Business Combination on the Closing Date, the Company received net cash proceeds of $801.8 million. As of December 31, 2023, the Company had cash and cash equivalents of $464.6 million, which management believes will be sufficient to fund the Company’s current operating plan for at least the next 12 months from the date these consolidated financial statements were issued. There can be no assurance that the Company will be successful in achieving its business plans, that the Company’s current capital will be sufficient to support its ongoing business plans, or that any additional financing will be available in a timely manner or on acceptable terms, if at all. If the Company’s business plans require it to raise additional capital, but the Company is unable to do so, it may be required to alter, or scale back its aircraft design, development and certification programs, as well as its manufacturing capabilities, or be unable to fund capital expenditures. Any such events would have a material adverse effect on the Company’s financial position, results of operations, cash flows, and ability to achieve the Company’s intended business plans.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
Summary of Significant Accounting Policies	Dec. 31, 2023
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation The accompanying consolidated financial statements have been prepared in conformity with U.S. GAAP and include the accounts of the Company. Use of Estimates The preparation of the consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent liabilities at the date of the consolidated financial statements and the reported amounts of expenses during the reporting period. On an ongoing basis, management evaluates its estimates, including those related to the: (i) realization of deferred tax assets and estimates of tax liabilities, (ii) fair value of debt, (iii) fair value of share-based payments, (iv) valuation of leased assets and liabilities, and (v) estimated useful lives of long-lived assets. These estimates are based on historical data and experience, as well as various other factors that management believes to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying value of assets and liabilities that are not readily apparent from other sources. Such estimates often require the selection of appropriate valuation methodologies and models and may involve significant judgment in evaluating ranges of assumptions and financial inputs. Actual results may differ from those estimates under different assumptions, financial inputs, or circumstances. Retroactive Application of Reverse Recapitalization As discussed in Note 4 - Reverse Recapitalization and Related Transactions, the Business Combination was accounted for as a reverse recapitalization of equity structure. Pursuant to U.S. GAAP, the Company retrospectively recast its weighted-average outstanding shares within the Company’s consolidated statement of operations for the year ended December 31, 2021. As part of the closing, all of Legacy Archer’s issued Series Seed redeemable convertible preferred stock and Series A redeemable convertible preferred stock were converted into Legacy Archer common stock, which were converted again, along with all other issued and outstanding common stock of Legacy Archer, into New Archer Class A common stock and New Archer Class B common stock. The basic and diluted weighted-average Legacy Archer common stock were retroactively converted to New Archer Class A common stock and New Archer Class B common stock to conform to the recast in the consolidated statements of stockholders’ equity. Cash, Cash Equivalents, and Restricted Cash Cash consists of cash on deposit with financial institutions. Cash equivalents consist of short-term, highly liquid financial instruments that are readily convertible to cash and have maturities of three months or less from the date of purchase. As of December 31, 2023 and 2022, the Company’s cash and cash equivalents included money market funds of $339.6 million and $6.1 million, respectively. Restricted cash consists primarily of cash held as security for the Company’s standby letters of credit. Refer to Note 8 - Commitments and Contingencies for further details. The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported in the consolidated balance sheets that sum to amounts reported on the consolidated statements of cash flows (in millions): As of December 31, 2023 2022 Cash and cash equivalents $ 464.6 $ 69.4 Restricted cash 6.9 2.9 Total cash, cash equivalents, and restricted cash $ 471.5 $ 72.3 Short-Term Investments The Company had short-term investments in marketable securities with original maturities of less than one year, including U.S. Treasury securities, corporate debt securities and commercial paper. The Company classifies its marketable securities as available-for-sale at the time of purchase and reevaluates such classification at each balance sheet date. These marketable securities are carried at fair value, and unrealized gains and losses are recorded in other comprehensive loss in the consolidated statements of comprehensive loss, which is reflected as a component of stockholders’ equity. These marketable securities are assessed as to whether those with unrealized loss positions are other than temporarily impaired. The Company considers impairments to be other than temporary if they are related to deterioration in credit risk or if it is likely the securities will be sold before the recovery of their cost basis. If the impairment is deemed other than temporary, the security is written down to its fair value and a loss is recognized in other (expense) income, net. Realized gains and losses from the sale of marketable securities and from declines in value deemed to be other than temporary are determined based on the specific identification method and recognized in other (expense) income, net in the consolidated statements of operations. Fair Value Measurements The Company applies the provisions of Accounting Standards Codification (“ASC”) 820, Fair Value Measurement, which defines a single authoritative definition of fair value, sets out a framework for measuring fair value, and expands on required disclosures about fair value measurements. The provisions of ASC 820 relate to financial assets and liabilities as well as other assets and liabilities carried at fair value on a recurring and nonrecurring basis. The standard clarifies that fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, the standard establishes a three-tier value hierarchy, which prioritizes the inputs used in measuring fair value as follows: Level 1 Unadjusted quoted prices in active markets for identical assets or liabilities accessible to the reporting entity at the measurement date. Level 2 Other than quoted prices included in Level 1 inputs that are observable for the asset or liability, either directly or indirectly, for substantially the full term of the asset or liability. Level 3 Unobservable inputs for the asset or liability used to measure fair value to the extent that observable inputs are not available, thereby allowing for situations in which there is little, if any, market activity for the asset or liability at the measurement date. The carrying amounts of the Company’s cash, accounts payable, accrued compensation, and accrued liabilities approximate their fair values due to the short-term nature of these instruments. The following tables present information about the Company’s assets and liabilities that are measured at fair value on a recurring basis as of December 31, 2023 and 2022 and indicate the fair value hierarchy of the valuation inputs the Company utilized to determine such fair value (in millions): As of December 31, 2023 Description Level 1 Level 2 Level 3 Total Assets: Cash equivalents: Money market funds $ 339.6 $ — $ — $ 339.6 Liabilities: Warrant liability – public warrants $ 25.4 $ — $ — $ 25.4 Warrant liability – private placement warrants $ — $ — $ 14.5 $ 14.5 Accrued technology and dispute resolutions agreements liability $ — $ — $ 44.0 $ 44.0 As of December 31, 2022 Description Level 1 Level 2 Level 3 Total Assets: Cash equivalents: Money market funds $ 6.1 $ — $ — $ 6.1 Short-term investments: U.S. Treasury securities $ 316.6 $ — $ — $ 316.6 Corporate debt securities $ — $ 20.1 $ — $ 20.1 Commercial paper $ — $ 125.1 $ — $ 125.1 Liabilities: Warrant liability – public warrants $ 4.5 $ — $ — $ 4.5 Warrant liability – private placement warrants $ — $ — $ 2.5 $ 2.5 Cash Equivalents The Company’s cash equivalents consist of short-term, highly liquid financial instruments that are readily convertible to cash and have maturities of three months or less from the date of purchase. The Company classifies its money market funds as Level 1, because they are valued based on quoted market prices in active markets. Short-Term Investments The Company’s short-term investments consisted of high quality, investment grade marketable securities and were classified as available-for-sale. The Company classifies its investments in U.S. Treasury securities as Level 1, because they are valued using quoted market prices in active markets. The Company classifies its investments in corporate debt securities and commercial paper as Level 2, because they are valued using inputs other than quoted prices which are directly or indirectly observable in the market, including readily available pricing sources for the identical underlying security which may not be actively traded. The following tables present a summary of the Company’s cash equivalents and short-term investments as of December 31, 2023 and 2022 (in millions): As of December 31, 2023 Description Amortized Cost Unrealized Gains Unrealized Losses Fair Value Cash equivalents: Money market funds $ 339.6 $ — $ — $ 339.6 Total $ 339.6 $ — $ — $ 339.6 As of December 31, 2022 Description Amortized Cost Unrealized Gains Unrealized Losses Fair Value Cash equivalents: Money market funds $ 6.1 $ — $ — $ 6.1 Short-term investments: U.S. Treasury securities 317.4 — (0.8) 316.6 Corporate debt securities 20.1 — — 20.1 Commercial paper 125.1 — — 125.1 Total $ 468.7 $ — $ (0.8) $ 467.9 The unrealized losses related to the Company’s short-term investments were primarily due to changes in interest rates and not due to increased credit risk or other valuation concerns. T he Company had no other-than-temporary impairments for the years ended December 31, 2023, 2022 and 2021 . Public Warrants The measurement of the public warrants as of December 31, 2023 is classified as Level 1 due to the use of an observable market quote in an active market under the ticker “ACHR WS”. The quoted price of the public warrants was $1.46 and $0.26 per warrant as of December 31, 2023 and 2022, respectively. Private Placement Warrants The Company utilizes a Monte Carlo simulation model for the private placement warrants at each reporting period, with changes in fair value recognized in the consolidated statements of operations. The estimated fair value of the private placement warrant liability is determined using Level 3 inputs. Inherent in a Monte Carlo simulation model are assumptions related to expected share-price volatility, expected life, risk-free interest rate, and dividend yield. The key inputs into the Monte Carlo simulation model for the private placement warrants are as follows: Input December 31, December 31, Stock price $ 6.14 $ 1.87 Strike price $ 11.50 $ 11.50 Dividend yield 0.00 % 0.00 % Term (in years) 2.71 3.71 Volatility 70.15 % 75.00 % Risk-free rate 4.03 % 4.14 % Accrued Technology and Dispute Resolution Agreements Liability Under the Technology and Dispute Resolution Agreements, the Company recognized an accrued technology and dispute resolution agreements liability related to the unvested warrants for the Second Tranche (capitalized terms defined below). See Note 8 - Commitments and Contingencies for further details. The Company utilizes a Monte Carlo simulation model for the accrued technology and dispute resolution agreements liability at each reporting period, with changes in fair value recognized in the consolidated statements of operations. The estimated fair value of the accrued technology and dispute resolution agreements liability is determined using Level 3 inputs. Inherent in a Monte Carlo simulation model are assumptions related to expected share-price volatility, expected life, risk-free interest rate, and dividend yield. The key inputs into the Monte Carlo simulation model for the accrued technology and dispute resolution agreements liability are as follows: Input December 31, Stock price $ 6.14 Strike price $ 0.01 Dividend yield 0.00 % Term (in years) 0.11 Volatility 60.00 % Risk-free rate 5.40 % The following table presents the change in fair value of the Company’s Level 3 private placement warrants and accrued technology and dispute resolution agreements liability during the years ended December 31, 2023 and 2022 (in millions): Balance as of December 31, 2021 $ 10.1 Change in fair value (7.6) Balance as of December 31, 2022 2.5 Additions: accrued technology and dispute resolution agreements liability 48.0 Change in fair value 8.0 Balance as of December 31, 2023 (1) $ 58.5 (1) As of December 31, 2023, $14.5 million and $44.0 million were recorded within warrant liabilities and accrued expenses and other current liabilities, respectively, in the consolidated balance sheets. In connection with changes in the fair value of the Company’s public and private placement warrants, the Company recognized a loss of $32.9 million during the year ended December 31, 2023 and a gain of $23.3 million and $10.4 million during the years ended December 31, 2022 and 2021, respectively, within other (expense) income, net in the consolidated statements of operations. Refer to Note 12 - Liability Classified Warrants for additional information about the public and private placement warrants. In connection with the change in fair value of the accrued technology and dispute resolution agreements liability, the Company recognized a gain of $4.0 million within general and administrative expenses in the consolidated statements of operations during the year ended December 31, 2023. Refer to Note 8 - Commitments and Contingencies for additional information about the accrued technology and dispute resolution agreements liability. Financial Instruments Not Recorded at Fair Value on a Recurring Basis Certain financial instruments, including debt, are not measured at fair value on a recurring basis in the consolidated balance sheets. The fair value of debt as of December 31, 2023 approximates its carrying value (Level 2). Refer to Note 7 - Notes Payable for additional information. Assets and Liabilities Recorded at Fair Value on a Non-Recurring Basis Certain assets and liabilities are subject to measurement at fair value on a non-recurring basis if there are indicators of impairment or if they are deemed to be impaired as a result of an impairment review. Intangible Assets, Net Intangible assets consist solely of domain names and are recorded at cost, net of accumulated amortization, and if applicable, impairment charges. Amortization of domain names is provided over a 15-year estimated useful life on a straight-line basis or based on the pattern in which economic benefits are consumed, if reliably determinable. The Company reviews intangible assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. The Company has analyzed a variety of factors to determine if any circumstance could trigger an impairment loss, and, at this time and based on the information presently known, no event has occurred and indicated that it is more likely than not that an impairment loss has been incurred. Therefore, the Company did not record any impairment charges for its intangible assets for the years ended December 31, 2023, 2022 and 2021. As of December 31, 2023 and 2022, the net carrying amounts for domain names were $0.4 million and $0.4 million, respectively, and were recorded in the Company’s consolidated balance sheets. Property and Equipment, Net Property and equipment are stated at historical cost less accumulated depreciation. Expenditures for major renewals and betterment are capitalized, while minor replacements, maintenance, and repairs, which do not extend the asset lives, are charged to operations as incurred. Upon sale or disposition, the cost and related accumulated depreciation is removed from the accounts, and any difference between the selling price and net carrying amount is recorded as a gain or loss in the consolidated statements of operations. Depreciation on property and equipment is calculated using the straight-line method over the estimated useful lives of the assets as follows: Useful Life (In years) Furniture, fixtures, and equipment 5 Vehicles 5 Computer hardware 3 Computer software 3 Website design 2 Leasehold improvements Shorter of lease term or the asset standard life Impairment of Long-Lived Assets The Company reviews its long-lived assets, consisting primarily of property and equipment, for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable. Such triggering events or changes in circumstances may include: a significant decrease in the market price of a long-lived asset, a significant adverse change in the extent or manner in which a long-lived asset is being or intended to be used, a significant adverse change in legal factors or in the business climate, the impact of competition or other factors that could affect the value of a long-lived asset, a significant adverse deterioration in the amount of revenue or cash flows expected to be generated from an asset group, an accumulation of costs significantly in excess of the amount originally expected for the acquisition or development of a long-lived asset, current or future operating or cash flow losses that demonstrate continuing losses associated with the use of a long-lived asset, or a current expectation that, more likely than not, a long-lived asset will be sold or otherwise disposed of significantly before the end of its previously estimated useful life. The Company performs impairment testing at the asset group level that represents the lowest level for which identifiable cash flows are largely independent of the cash flows of other assets and liabilities. Recoverability of these assets is determined by comparing the forecasted undiscounted cash flows attributable to such assets including any cash flows upon their eventual disposition to their carrying value. If the carrying value of the assets exceeds the forecasted undiscounted cash flows, then the assets are written down to their fair value. The Company did not identify any events or changes in circumstances that would indicate that the Company’s long-lived assets may be impaired and therefore determined there was no impairment of long-lived assets during all periods presented. Cloud Computing Arrangements The Company capitalizes certain implementation costs incurred in the application development stage of projects related to its cloud computing arrangements that are service contracts. Capitalized implementation costs are recognized in other long-term assets in the consolidated balance sheets and amortized on a straight-line basis over the fixed, noncancellable term of the associated hosting arrangement plus any reasonably certain renewal periods. Costs related to preliminary project activities and post-implementation activities are expensed as incurred. As of December 31, 2023 and 2022, the net carrying amounts of the Company’s capitalized cloud computing implementation costs were $6.4 million and $3.7 million, respectively. Contract Liabilities The Company records contract liabilities related to differences between the timing of cash receipts from the customer and the recognition of revenue. As of December 31, 2023 and 2022, the Company’s contract liability balances were $10.8 million and $10.0 million, respectively, and recorded in other long-term liabilities in the Company’s consolidated balance sheets. As of December 31, 2023, the Company’s contract liabilities consisted of a $10.0 million pre-delivery payment received from United Airlines, Inc. (“United”) under the terms of the Amended United Purchase Agreement (defined below) (see Note 10 - Stock-Based Compensation), and a $0.8 million installment payment received under a contract order with the United States Air Force for the design, development, and ground test of the Company’s production aircraft, Midnight. As of December 31, 2022, the Company’s contract liabilities consisted of the $10.0 million pre-delivery payment received from United, as discussed above. No revenues were recognized during the years ended December 31, 2023, 2022 and 2021. Operating Expenses Research and Development Research and development (“R&D”) costs are expensed as incurred and are primarily comprised of personnel-related costs including salaries, bonuses, benefits, and stock-based compensation for employees focused on R&D activities, costs associated with building prototype aircraft, other related costs, depreciation, and an allocation of general overhead. R&D efforts focus on the design and development of the Company’s eVTOL aircraft, including certain of the systems that are used in it. General and Administrative General and administrative expenses are primarily comprised of personnel-related costs including salaries, bonuses, benefits, and stock-based compensation for employees associated with the Company’s administrative services such as finance, legal, human resources, and information technology, other related costs, depreciation, and an allocation of general overhead. General and administrative expenses include non-cash charges relating to the Technology and Dispute Resolution Agreements (defined below) for the year ended December 31, 2023 and stock-based compensation expense related to restricted stock units (“RSUs”) granted to the Company’s founders pursuant to the terms and conditions of the Business Combination Agreement immediately prior to closing (the “Founder Grants”) for the years ended December 31, 2023, 2022 and 2021. Refer to Note 8 - Commitments and Contingencies and Note 10 - Stock-Based Compensation for additional information. Other Warrant Expense Other warrant expense consists entirely of non-cash expense related to the warrants issued in conjunction with the execution of the purchase agreement (“United Purchase Agreement”), collaboration agreement (“United Collaboration Agreement”), and warrant agreement (“United Warrant Agreement”) with United. Refer to Note 10 - Stock-Based Compensation for additional information. Stock-Based Compensation The Company’s stock-based compensation awards consist of options granted to employees and non-employees and RSUs granted to employees, directors, and non-employees that convert into shares of the Company’s Class A common stock upon vesting. The Company recognizes stock-based compensation expense in accordance with the provisions of ASC 718, Compensation - Stock Compensation . ASC 718 requires the measurement and recognition of compensation expense for all stock-based compensation awards made to employees, directors, and non-employees to be based on the grant date fair values of the awards. The Company estimates the fair value of stock options using the Black-Scholes option-pricing model. The value of the award is recognized as expense over the requisite service period on a straight-line basis. Determining the grant date fair value of the awards using the Black-Scholes option-pricing model requires management to make assumptions and judgments, including but not limited to the following: Expected term — The estimate of the expected term of employee awards is determined in accordance with the simplified method, which estimates the term based on an averaging of the vesting period and contractual term of the option grant. The Company uses the contractual term for non-employee awards. Expected volatility — Since the Company does not have sufficient historical data on the volatility of its common stock, the expected volatility used is based on the volatility of similar entities (referred to as “guideline companies”) for a period consistent with the expected term of the award. Risk-free interest rate — The risk-free interest rate used to value awards is based on the United States Treasury yield in effect at the time of grant for a period consistent with the expected term of the award. Dividend yield — The Company has never declared or paid any cash dividends and does not presently plan to pay cash dividends in the foreseeable future. Forfeiture rate — The Company has elected to account for forfeitures as they occur and will record stock-based compensation expense assuming all option holders will complete the requisite service period. If an employee forfeits an award because they fail to complete the requisite service period, the Company will reverse stock-based compensation expense previously recognized in the period the award is forfeited. The Company has not issued any stock options since the closing of the Business Combination. Fair Value of Common Stock The Company’s Board of Directors grants stock options with exercise prices equal to the fair value of the Company’s common stock on the date of grant. Prior to the closing of the Business Combination, the Company determined the fair value of its common stock at the time of the grant of stock options in accordance with the American Institute of Certified Public Accountants (“AICPA”) Accounting and Valuation Guide: Valuation of Privately-Held-Company Equity Securities Issued as Compensation (the “AICPA Practice Aid”). The Company determined the fair value of its common stock based on a variety of factors including, but not limited to (i) the results of contemporaneous independent third-party valuations of the Company’s common stock and the prices, rights, preferences and privileges of the Company’s redeemable convertible preferred stock relative to those of the Company’s common stock; (ii) the lack of marketability of the Company’s common stock; (iii) actual operating and financial results; (iv) current business conditions and projections; (v) the likelihood of achieving a liquidity event, such as an IPO or sale of the Company, given prevailing market conditions; and (vi) precedent transactions involving the Company’s shares. As provided in the AICPA Practice Aid, there are several approaches for setting the value of an enterprise and various methodologies for allocating the value of an enterprise to its outstanding equity. The Company determined the fair value of equity awards using a combination of the market and income approach. Within the market approach, the guideline public company method was used, which employs the use of ratios developed from the market price of traded shares from publicly traded companies considered reasonably similar to the Company. Under the income approach, the enterprise value was estimated using the discounted cash flow method, which involves estimating the future cash flows of a business for a discrete period and discounting them to their present value. In allocating enterprise value to the Company’s outstanding equity, the Company applied a hybrid approach, which consisted of the option pricing method (“OPM”) and probability-weighted expected return method (“PWERM”). The OPM treats securities, including debt, common and preferred stock, as call options on the enterprise’s value, with exercise prices based on the securities’ respective liquidation preferences and conversion values. The PWERM estimates the fair market value of the common stock based on an analysis of future values for the enterprise assuming various exit scenarios, such as IPO, merger or sale, staying private, and liquidation. Since there was no active market for the Company’s common stock, the Company also applied a discount for lack of marketability for both OPM and PWERM scenarios. In conducting the valuations, the Company considered all objective and subjective factors that the Company believed to be relevant in the valuation conducted, including management’s best estimate of the Company’s business condition, and prospects and operating performance at the valuation dates. There are significant judgments and estimates inherent in these valuations. Since the closing of the Business Combination, the fair value of the Company’s common stock is based on the closing price of the Company’s Class A common stock, as quoted on the NYSE, on the date of grant. Leases The Company accounts for leases in accordance with ASC 842, Leases , and determines if an arrangement is a lease at its inception. Right-of-use (“ROU”) assets and liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term. The Company uses its estimated incremental borrowing rate in determining the present value of lease payments considering the term of the lease, which is derived from information available at the lease commencement date. The incremental borrowing rate is the rate of interest the Company would have to pay to borrow, on a collateralized basis, an amount equal to the lease payments for a term similar to the lease term in a similar economic environment as the lease. The lease term includes renewal options when it is reasonably certain that the option will be exercised and excludes termination options. To the extent that the Company’s agreements have variable lease payments, the Company includes variable lease payments that depend on an index or a rate and excludes those that depend on facts or circumstances occurring after the commencement date, other than the passage of time. Lease expense for leases is recognized on a straight-line basis over the lease term. The Company has elected not to recognize ROU assets and lease liabilities that arise from short-term (12 months or less) leases for any class of underlying asset. In addition, the Company has elected as an accounting policy, the practical expedient to not separate lease and non-lease components within a contract and instead treat it as a single lease component. Operating leases are included in ROU assets, current portion of lease liabilities, and lease liabilities, net of current portion in the Company’s consolidated balance sheets. Income Taxes The Company accounts for its income taxes using the asset and liability method whereby deferred tax assets and liabilities are determined based on temporary differences between the basis used for financial reporting and income tax reporting purposes. Deferred income taxes are provided based on the enacted tax rates in effect at the time such temporary differences are expected to reverse. A valuation allowance is provided for deferred tax assets if it is more-likely-than-not that the Company will not realize those tax assets through future operations. Significant judgment is applied when assessing the need for valuation allowances and includes the evaluation of historical income (loss) adjusted for the effects of non-recurring items. Areas of estimation include consideration of future taxable income. The Company has placed a full valuation allowance against its federal and state deferred tax assets since the recovery of the assets is uncertain. Should a change in circumstances lead to a change in judgment about the utilization of deferred tax assets in future years, the adjustment related to valuation allowances would be reported as an increase to income. The Company utilizes the guidance in ASC 740-10, Income Taxes , to account for uncertain tax positions. ASC 740-10 contains a two-step approach to recognizing and measuring uncertain tax positions. The first step is to evaluate the tax position for recognition by determining if the weight of available evidence indicates it is more-likely-than-not that the positions will be sustained on audit, including resolution of related appeals or litigation processes, if any. The second step is to measure the tax benefit as the largest amount which is more-likely-than-not of being realized and effectively settled. An uncertain income tax position will not be recognized if it has less than a 50% likelihood of being sustained. The Company considers many factors when evaluating and estimating its tax positions and tax benefits, which may require periodic adjustments and which may not accurately forecast actual outcomes. The Company’s policy is to recognize interest and penalties related to uncertain tax positions, if any, in the income tax provision. Net Loss Per Share Basic net loss per share is calculated by dividing net loss attributable to common stockholders by the weighted-average number of common shares outstanding. For all periods presented, the calculation of basic net loss per share excludes shares issued upon the early exercise of stock options where the vesting conditions have not been satisfied. Common stock purchased pursuant to an early exercise of stock options is not deemed to be outstanding for accounting purposes until those shares vest. The Company also excludes unvested shares sub

Reverse Recapitalization and Re

Reverse Recapitalization and Related Transactions	12 Months Ended
Reverse Recapitalization and Related Transactions	Dec. 31, 2023
Reverse Recapitalization [Abstract]
Reverse Recapitalization and Related Transactions	Reverse Recapitalization and Related Transactions Upon the consummation of the Business Combination on September 16, 2021, in accordance with the terms and conditions of the Business Combination Agreement, all issued and outstanding Legacy Archer common stock was converted into shares of common stock of New Archer at an exchange ratio of 1.00656519 (the “Exchange Ratio”). Additionally, upon closing the Business Combination, Legacy Archer received $257.6 million in cash proceeds released from Atlas’ trust account, after redemptions of $242.4 million. At the closing of the Business Combination, each non-redeemed outstanding share of Atlas Class A common stock was converted into one share of Class A common stock of New Archer. Upon consummation of the Business Combination, the shares of Legacy Archer held by Legacy Archer stockholders converted into 124,735,762 shares of common stock of New Archer, including 54,987,838 shares of Class A common stock and 69,747,924 shares of Class B common stock. While the legal acquirer in the Business Combination was Atlas, for accounting and financial reporting purposes under U.S. GAAP, Legacy Archer is the accounting acquirer and the Business Combination was accounted for as a “reverse recapitalization.” A reverse recapitalization does not result in a new basis of accounting, and the financial statements of the combined entity represent the continuation of the financial statements of Legacy Archer in many respects. Under this method of accounting, Atlas was treated as the “acquired” company. Accordingly, the consolidated assets, liabilities, and results of operations of Legacy Archer became the historical financial statements of New Archer, and Atlas’ assets and liabilities were consolidated with Legacy Archer’s on the Closing Date. Operations prior to the Business Combination are presented as those of New Archer in reports subsequent to the Closing Date. The net assets of Atlas were recognized at their carrying value immediately prior to the closing of the Business Combination with no goodwill or other intangible assets recorded and were as follows, net of transaction costs (in millions): Cash $ 201.8 Warrant liability (39.5) Net assets acquired $ 162.3 The Company accounted for the Business Combination as a tax-free reorganization. Additionally, as part of the recapitalization, 1,875,000 shares of Atlas Class A common stock held by Atlas Crest Investment LLC (the “Atlas Sponsor”) were exchanged with 1,875,000 shares of New Archer Class A common stock that will be subject to forfeiture if the vesting condition is not met over the three-year term following the Closing Date. The vesting condition states that these earn-out shares of New Archer Class A common stock will vest if the New Archer’s Class A common stock volume weighted-average price, as defined in the Amended and Restated Sponsor Letter Agreement, by and among Atlas Sponsor, Atlas, Legacy Archer, and the individuals named therein, is greater than or equal to $12.00 per share for any period of ten (10) trading days out of twenty (20) consecutive trading days. The earn-out shares were recognized at fair value upon the closing of the Business Combination and classified in stockholders’ equity (with no net impact to additional paid-in-capital) since the earn-out shares were determined to be indexed to the Company’s own equity and meet the requirements for equity classification. Pursuant to the terms of the Business Combination Agreement, all of the issued and outstanding series seed redeemable convertible preferred stock and series A redeemable convertible preferred stock converted into 64,884,120 shares of Legacy Archer common stock immediately prior to the Business Combination. Then, as of the closing of the Business Combination, all outstanding shares of Legacy Archer common stock converted into 124,735,762 shares of New Archer Class A and B common stock. Additionally, each of Legacy Archer options, RSUs, and warrants that were outstanding immediately prior to the closing of the Business Combination remained outstanding and converted into options, RSUs, and warrants for New Archer Class A and Class B common stock equal to the number of the Company’s common stock, subject to such options, RSUs, or warrants, multiplied by the Exchange Ratio at an exercise price per share equal to the current exercise price per share for such option or warrant divided by the Exchange Ratio, with the aggregate number of shares of New Archer Class A and B common stock issuable upon exercise of such options, RSUs, and warrants to be 60,260,483. Additionally, 10,004,612 of outstanding RSUs vested at the closing of the Business Combination into New Archer Class B common stock. Substantially concurrently with the execution of the Business Combination Agreement, Atlas entered into Subscription Agreements (the “Subscription Agreements”) with certain investors in the PIPE Financing (the “Subscription Investors”). Pursuant to the Subscription Agreements, the Subscription Investors agreed to purchase, and Atlas agreed to sell to the Subscription Investors, an aggregate of 60,000,000 shares of New Archer Class A common stock for a purchase price of $10.00 per share, or an aggregate of $600.0 million in gross cash proceeds. Pursuant to the Subscription Agreements, Atlas granted certain registration rights to the Subscription Investors with respect to the shares issued and sold in the PIPE Financing. The closing of the PIPE Financing occurred immediately prior to the closing of the Business Combination. In conjunction with the PIPE Financing, 1,512,500 shares of New Archer Class A common stock were issued to satisfy certain fees related to the Business Combination and PIPE Financing. The number of shares of common stock issued immediately following the consummation of the Business Combination were as follows: Number of shares Class A and B common stock outstanding on July 1, 2021 52,572,374 Common stock issued through option exercises between July 1, 2021 and September 16, 2021 4,738,344 Vesting of unvested shares between July 1, 2021 and September 16, 2021 2,540,925 Common stock outstanding prior to the Business Combination 59,851,643 Conversion of preferred stock 64,884,120 Common stock attributable to Atlas 36,385,693 Adjustment related to reverse recapitalization* 101,269,813 Restricted stock units vested at closing 10,004,612 Common stock attributable to PIPE Financing 61,512,500 Total shares of common stock as of closing of the Business Combination and related transactions as of September 16, 2021 232,638,568 * The corresponding adjustment to additional paid-in-capital related to the reverse recapitalization was comprised of (i) $162.3 million which represents the fair value of the consideration transferred in the Business Combination, less the excess of the fair value of the shares issued over the value of the net monetary assets of Atlas, net of transaction costs and (ii) $61.5 million which represents the conversion of the convertible preferred stock into New Archer Class A and Class B common stock. At the Closing Date, Legacy Archer had 56,390,023 outstanding options and RSUs under the 2019 Plan (as defined below) in addition to 13,112,602 outstanding warrants, which remained outstanding and converted into 70,265,095 options, RSUs, and warrants in New Archer Class A or B common stock, as derived by multiplying the number of Legacy Archer common stock subject to such option or warrant by the Exchange Ratio. In addition, of the RSUs outstanding immediately prior to the closing of the Business Combination, 10,004,612 vested at closing into New Archer Class B common stock. The options and warrants shall be exercised at an exercise price per share equal to the current exercise price per share for such option or warrant divided by the Exchange Ratio. Following the Business Combination, Atlas’ warrants to purchase 24,666,667 shares of New Archer Class A common stock, consisting of (i) 16,666,667 public warrants listed on the NYSE and (ii) 8,000,000 private warrants, each with an exercise price of $11.50 per share, remained outstanding. As part of the closing, total direct and incremental transaction costs aggregated $81.8 million, of which $10.9 million was expensed as part of the Business Combination, $55.8 million was recorded to additional paid-in-capital as equity issuance costs, and the remaining $15.1 million was settled through the issuance of shares of New Archer Class A common stock.

Property and Equipment, Net

Property and Equipment, Net	12 Months Ended
Property and Equipment, Net	Dec. 31, 2023
Property, Plant and Equipment [Abstract]
Property and Equipment, Net	Property and Equipment, Net Property and equipment, net, consisted of the following (in millions): As of December 31, 2023 2022 Furniture, fixtures, and equipment $ 7.9 $ 1.5 Vehicles 0.1 — Computer hardware 5.3 4.5 Computer software 1.5 0.7 Website design 0.8 0.7 Leasehold improvements 33.0 2.9 Construction in progress 18.4 4.8 Total property and equipment 67.0 15.1 Less: Accumulated depreciation (9.4) (3.6) Total property and equipment, net $ 57.6 $ 11.5 Construction in progress includes costs incurred for the Company’s manufacturing facilities to be constructed in Covington, Georgia and other assets that have not yet been placed in service. The following table presents depreciation expense included in each respective expense category in the consolidated statements of operations (in millions): Year Ended December 31, 2023 2022 2021 Research and development $ 5.3 $ 2.3 $ 0.9 General and administrative 0.5 0.8 0.4 Total depreciation expense $ 5.8 $ 3.1 $ 1.3

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	12 Months Ended
Accrued Expenses and Other Current Liabilities	Dec. 31, 2023
Other Liabilities Disclosure [Abstract]
Accrued Expenses and Other Current Liabilities	Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consisted of the following (in millions): As of December 31, 2023 2022 Accrued professional fees $ 9.5 $ 17.2 Accrued employee costs 16.7 7.8 Accrued parts and materials 12.1 5.2 Taxes payable 1.4 0.3 Accrued capital expenditures 9.2 2.9 Accrued cloud computing implementation costs 0.3 2.0 Accrued marketing fees — 0.2 Accrued technology and dispute resolution agreements liability (Note 8 ) 44.0 — Other current liabilities 3.7 1.1 Total $ 96.9 $ 36.7

Notes Payable

Notes Payable	12 Months Ended
Notes Payable	Dec. 31, 2023
Debt Disclosure [Abstract]
Notes Payable	Notes Payable The Company’s notes payable consisted of the following (in millions): As of December 31, 2023 2022 Synovus Bank Loan $ 7.5 $ — Loan unamortized discount and loan issuance costs (0.3) — Silicon Valley Bank (“SVB”) Term Loans — 10.0 Term Loans unamortized discount and loan issuance costs — (0.7) Total debt, net of discount and loan issuance costs 7.2 9.3 Less current portion, net of discount and loan issuance costs — (9.3) Total long-term notes payable, net of discount and loan issuance costs $ 7.2 $ — Synovus Bank Loan On October 5, 2023, the Company entered into a credit agreement (the “Credit Agreement”) with Synovus Bank, as administrative agent and lender, and the additional lenders (the “Lenders”) from time to time. The Company may request the Lenders to provide multiple term loan advances (together, the “Loan”) in an aggregate principal amount of up to $65.0 million for the construction and development of the Company’s manufacturing facility in Covington, Georgia. The Company is required to make 120 monthly interest payments from November 14, 2023 until maturity, and 84 equal monthly principal installments from November 14, 2026 until maturity. The Credit Agreement matures on the earlier of October 5, 2033 or the date on which the outstanding Loan has been declared or automatically becomes due and payable pursuant to the terms of the Credit Agreement. The interest rate on the Loan is a floating rate per annum equal to secured overnight financing rate (“SOFR”) Rate (as defined in the Credit Agreement) plus the applicable margin of 2.00%, which increases by 5% per annum upon the occurrence of an event of default. The Company’s obligations under the Credit Agreement are secured by funds in a collateral account. Two of its direct subsidiaries are required to guarantee the Credit Agreement. The Company may prepay with certain premium that links to the passage of time, and in certain circumstances would be required to prepay the Loan under the Credit Agreement without payment of a premium. The Credit Agreement contains customary representations and warranties, customary affirmative and negative covenants, and customary events of default. As of December 31, 2023, the Company was in compliance with all the covenants of the Credit Agreement. The Company has drawn down $7.5 million of the Loan as of December 31, 2023. The effective interest rate for the draw downs ranged from 7.66% to 8.17% as of December 31, 2023. The Company incurred issuance costs of $0.3 million related to the loan outstanding as of December 31, 2023. The loan issuance costs will be amortized to interest expense over the contractual term of the Loan. During the year ended December 31, 2023, the Company recognized interest expense of $0.1 million, including an immaterial amount related to the amortization of issuance costs within interest income (expense), net in the consolidated statements of operations. The carrying value of the Loan, net of unamortized issuance costs of $0.3 million was $7.2 million as of December 31, 2023. The future scheduled principal maturities of the Loan as of December 31, 2023 are as follows (in millions): 2024 $ — 2025 — 2026 0.1 2027 0.3 2028 0.3 2029 and thereafter 6.8 $ 7.5 SVB Loan On July 9, 2021, the Company, as the borrower, entered into a Loan and Security Agreement (the “Loan and Security Agreement”) with SVB and SVB Innovation Credit Fund VIII, L.P. (“SVB Innovation”) as the lenders, and SVB as the collateral agent. The total principal amount of the loans is $20.0 million (the “Term Loans”), and all obligations due under the Term Loans are collateralized by all of the Company’s right, title, and interest in and to its specified personal property in favor of the collateral agent. The Term Loans include events of default and covenant provisions, whereby accelerated repayment may result if the Company were to default. On January 1, 2022, the Company began repaying the Term Loans, which are payable in 24 equal monthly installments, including principal and interest. The interest rate on the loans is a floating rate per annum equal to the greater of (i) 8.5% and (ii) the Prime Rate plus the Prime Rate Margin (each as defined in the Loan and Security Agreement), which increases by 2% per annum upon the occurrence of an event of default. The effective interest rate as of December 31, 2023, 2022 and 2021 were 10.20%, 9.40% and 9.02%, respectively. For the years ended December 31, 2023, 2022 and 2021, the Company recognized interest expense of $0.6 million, $1.5 million and $0.9 million, respectively. Additionally, in conjunction with the issuance of the Term Loans, the Company issued 366,140 warrants to SVB and 366,140 warrants to SVB Innovation, totaling 732,280 warrants. The Company issued the warrants to the lenders as consideration for entering into the Term Loans, representing a loan issuance fee. Each warrant provides SVB and SVB Innovation with the right to purchase one share of the Company’s Class A common stock. The Company recorded the warrants as liabilities at their fair value and adjusts the warrants to fair value at each reporting period. This liability is subject to remeasurement at each balance sheet date until exercised, and any change in fair value is recognized as a gain or loss in the Company’s consolidated statements of operations. The initial offsetting entry to the warrant liability was a debt discount recorded to reflect the loan issuance fee. See Note 12 - Liability Classified Warrants for further details. Effective March 27, 2023, the Term Loans and warrants were assigned to and assumed by First-Citizens Bank & Trust Company on the original terms and conditions of the financial instruments. Upon the closing of the Business Combination, the SVB warrants became public warrants. The subsequent measurement of the SVB warrants as of December 31, 2023 is classified as Level 1 due to the use of an observable market quote in an active market under the ticker “ACHR WS”. The quoted price of the public warrants was $1.46 as of December 31, 2023. During the years ended December 31, 2023, 2022 and 2021, the Company recognized interest expense of $0.7 million, $0.5 million and $0.2 million related to the amortization of the discount and loan issuance costs, respectively. As of December 31, 2023, the Term Loans were fully repaid and the discount and loan issuance costs were fully amortized.

Commitment and Contingencies

Commitment and Contingencies	12 Months Ended
Commitment and Contingencies	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Operating Leases The Company leases office, lab, hangar, and storage facilities under various operating lease agreements with lease periods expiring between 2024 and 2030 and generally containing periodic rent increases and various renewal and termination options. The Company’s lease costs were as follows (in millions): Year Ended December 31, 2023 2022 2021 Operating lease cost $ 5.7 $ 5.8 $ 2.1 Short-term lease cost 0.6 0.2 — Total lease cost $ 6.3 $ 6.0 $ 2.1 The Company’s weighted-average remaining lease term and discount rate as of December 31, 2023 and 2022 were as follows: 2023 2022 Weighted-average remaining lease term (in months) 58 46 Weighted-average discount rate 14.74 % 13.78 % The minimum aggregate future obligations under the Company’s non-cancelable operating leases as of December 31, 2023 were as follows (in millions): 2024 $ 5.5 2025 5.1 2026 4.6 2027 2.2 2028 2.2 Thereafter 4.4 Total future lease payments 24.0 Less: leasehold improvement allowance (0.7) Total net future lease payments 23.3 Less: imputed interest (7.3) Present value of future lease payments $ 16.0 Supplemental cash flow information and non-cash activities related to right-of-use assets and lease liabilities were as follows (in millions): Year Ended December 31, 2023 2022 2021 Operating cash outflows from operating leases $ 5.0 $ 4.3 $ 1.9 Operating lease liabilities from obtaining right-of-use assets 0.6 11.7 3.6 Finance Lease In February 2023, the Company entered into a lease arrangement with the Newton County Industrial Development Authority (the “Authority”) for the Company’s manufacturing facilities to be constructed in Covington, Georgia. In connection with the lease arrangement, the Authority issued a taxable revenue bond (the “Bond”), which was acquired by the Company. The arrangement is structured so that the Company’s lease payments to the Authority equal and offset the Authority’s bond payments to the Company. Accordingly, the Company offsets the finance lease obligation and the Bond on its consolidated balance sheets. Letters of Credit On February 28, 2023, in conjunction with a project agreement that the Company entered into with the City of Covington and the Authority for the Company’s manufacturing facilities to be constructed in Covington, Georgia, the Company entered into a standby letter of credit in the amount of $3.5 million in favor of the City of Covington, to guarantee certain performance obligations. The standby letter of credit expires on March 31, 2035. As of December 31, 2023, the Company had standby letters of credit in the aggregate outstanding amount of $5.9 million, secured with restricted cash. Litigation During the ordinary course of the business, the Company may be subject to legal proceedings, various claims, and litigation. Such proceedings can be costly, time consuming, and unpredictable, and therefore, no assurance can be given that the final outcome of such proceedings will not materially impact the Company’s financial condition or results of operations. Wisk Litigation and Settlement On April 6, 2021, Wisk Aero LLC (“Wisk”) brought a lawsuit against the Company in the United States District Court for the Northern District of California (the “District Court”) alleging misappropriation of trade secrets and patent infringement. The Company has filed certain counterclaims for defamation, tortious interference and unfair competition. On August 10, 2023, the Company, the Boeing Company (“Boeing”) and Wisk entered into the Technology and Dispute Resolution Agreements (as defined below), which provided for, among other things, the resolution of the federal and state court litigation between the parties. On August 10, 2023, the Company, Boeing and Wisk entered into a series of agreements that provide for, among other things, for certain investments by Boeing into the Company and an autonomous flight technology collaboration between Wisk and the Company, the issuance of certain warrants to Wisk and resolution of the federal and state court litigation between the parties (the “Technology and Dispute Resolution Agreements”). Pursuant to a private placement transaction entered into by the Company on August 10, 2023, Boeing subscribed to purchase shares of the Company’s Class A common stock, par value $0.0001 per share (the “Common Stock”) (the “First Boeing Investment”), and received registration rights with respect to such shares of Common Stock and the shares of Common Stock underlying the Warrant (as defined below) pursuant to a registration rights agreement. Pursuant to the Technology and Dispute Resolution Agreements, the Company issued Wisk a warrant to purchase up to 13,176,895 shares of Common Stock with an exercise price of $0.01 per share (the “Wisk Warrant”). The Wisk Warrant shall vest and be exercisable as follows: (i) immediately as to 4,512,636 shares, underlying the Wisk Warrant (the “Initial Vested Share Tranche”) and (ii) for up to 8,664,259 shares (the “Second Tranche”) underlying the Wisk Warrant as determined six months from the effective date of the Warrant (the “Specified Date”). The extent to which the Second Tranche vests is based on the value of the First Boeing Investment and the shares underlying the Initial Vested Share Tranche as of the Specified Date. The companies are in discussions regarding certain terms under the Technology and Dispute Resolution Agreements, including any vesting under the Second Tranche and what, if any, additional value may be provided to Wisk. The Company recorded the Initial Vested Share Tranche within equity at its fair value. The Company recognized technology and dispute resolution agreements expense for the Initial Vested Share Tranche upon issuance. The Company recorded the Second Tranche as liabilities at their fair value and adjusts the warrants to fair value at each reporting period. This liability is subject to remeasurement at each balance sheet date until exercised, and any change in fair value is recognized as a gain or loss in the Company’s consolidated statements of operations. The initial offsetting entry to the warrant liability was technology and dispute resolution agreements expense. During the year ended December 31, 2023, the Company recorded a $70.3 million non-cash charge in general and administrative expenses consisting of a $26.3 million non-cash charge associated with the Initial Vested Share Tranche and a $44.0 million non-cash charge for the unvested portion of the Wisk Warrant that is subject to the vesting criteria described above and may never be realized.

Preferred and Common Stock

Preferred and Common Stock	12 Months Ended
Preferred and Common Stock	Dec. 31, 2023
Equity [Abstract]
Preferred and Common Stock	Preferred and Common Stock Preferred Stock As of December 31, 2023, no shares of preferred stock were outstanding, and the Company has no present plans to issue any shares of preferred stock. Class A and Class B Common Stock Except for voting rights and conversion rights, or as otherwise required by applicable law, the shares of the Company’s Class A common stock and Class B common stock have the same powers, preferences, and rights and rank equally, share ratable and are identical in all respects as to all matters. The rights, privileges, and preferences are as follows: Voting Holders of the Company’s Class A common stock are entitled to one vote per share on all matters to be voted upon by the stockholders, and holders of Class B common stock are entitled to ten votes per share on all matters to be voted upon by the stockholders. The holders of Class A common stock and Class B common stock will generally vote together as a single class on all matters submitted to a vote of the stockholders, unless otherwise required by Delaware law or the Company’s amended and restated certificate of incorporation. Dividends Holders of Class A common stock and Class B common stock are entitled to receive such dividends, if any, as may be declared from time to time by the Company’s Board of Directors in its discretion out of funds legally available therefor. No dividends on common stock have been declared by the Company’s Board of Directors through December 31, 2023, and the Company does not expect to pay dividends in the foreseeable future. Preemptive Rights Stockholders have no preemptive or other subscription rights and there are no sinking fund or redemption provisions applicable to Class A common stock and Class B common stock. Conversion Each share of Class B common stock is convertible at any time at the option of the holder into one share of Class A common stock. In addition, each share of Class B common stock will automatically convert into one share of Class A common stock upon transfer to a non-authorized holder. In addition, Class B common stock is subject to “sunset” provisions, under which all shares of Class B common stock will automatically convert into an equal number of shares of Class A common stock upon the earliest to occur of (i) the ten-year anniversary of the closing of the Business Combination, (ii) the date specified by the holders of two-thirds of the then outstanding Class B common stock, voting as a separate class, and (iii) when the number of Class B common stock represents less than 10% of the aggregate number of Class A common stock and Class B common stock then outstanding. In addition, each share of Class B common stock will automatically convert into an equal number of Class A common stock upon the earliest to occur of (a) in the case of a founder of the Company, the date that is nine months following the death or incapacity of such founder, and, in the case of any other holder, the date of the death or incapacity of such holder, (b) in the case of a founder of the Company, the date that is 12 months following the date that such founder ceases to provide services to the Company and its subsidiaries as an executive officer, employee or director of the Company, and, in the case of any other holder, immediately at the occurrence of any such event, and (c) in the case of a founder of the Company or any other holder, at least 80% (subject to customary capitalization adjustments) of the Class B common stock held by such founder or holder (on a fully as converted/as exercised basis) as of immediately following the closing of the Business Combination having been transferred (subject to exceptions for certain permitted transfers). During the years ended December 31, 2023, 2022 and 2021, 26,449,869, 8,406,170 and 5,337,446 shares of Class B common stock were converted into Class A common stock, respectively. Liquidation In the event of the Company’s voluntary or involuntary liquidation, dissolution, distribution of assets or winding-up, subject to preferences that may apply to any shares of preferred stock outstanding at the time, the holders of the Company’s common stock will be entitled to receive an equal amount per share of all of the Company’s assets of whatever kind available for distribution to stockholders, after the rights of the holders of any preferred stock have been satisfied. PIPE Financing On August 10, 2023, the Company entered into subscription agreements with certain investors providing for the private placement of 26,173,286 shares of the Company’s Class A common stock for net proceeds of approximately $139.0 million, after deducting offering costs. At-The-Market Offerings In November 2023, the Company entered into an Open Market Sales Agreement SM (the “Sales Agreement”) with Cantor Fitzgerald & Co., as the sales agent, pursuant to which the Company may offer and sell shares of the Company’s Class A common stock having an aggregate offering amount of up to $70.0 million. The Company will pay Cantor Fitzgerald & Co. a commission rate of up to 3.0% of the gross proceeds from the sale of any shares of Class A common stock pursuant to the Sales Agreement. During the year ended December 31, 2023, the Company sold 3,109,097 shares of Class A common stock for net proceeds of $19.5 million. As of December 31, 2023, the Company had $49.3 million remaining under the Sales Agreement.

Stock-Based Compensation_

Stock-Based Compensation	12 Months Ended
Stock-Based Compensation	Dec. 31, 2023
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation	Stock-Based Compensation Amended and Restated 2021 Plan In August 2021, the Company adopted the 2021 Equity Incentive Plan (the “2021 Plan”), which was approved by the stockholders of the Company in September 2021 and became effective immediately upon the closing of the Business Combination. In April 2022, the Company amended and restated the 2021 Plan (the “Amended and Restated 2021 Plan”), which was approved by the stockholders of the Company in June 2022. The aggregate number of shares of Class A common stock that may be issued under the plan increased to 34,175,708. In addition, the number of shares of Class A common stock reserved for issuance under the Amended and Restated 2021 Plan will automatically increase on January 1st of each year following this amendment, starting on January 1, 2023 and ending on (and including) January 1, 2031, in an amount equal to the lesser of (i) 5.0% of the total number of shares of Class A and Class B common stock outstanding on December 31 of the preceding year, or (ii) a lesser number of shares of Class A common stock determined by the Board of Directors prior to the date of the increase (the “EIP Evergreen Provision”). The EIP Evergreen Provision is calculated using the number of legally outstanding shares of common stock and includes shares, such as unvested shares pursuant to early exercised stock options, that are not considered outstanding for accounting purposes. In accordance therewith, the number of shares of Class A common stock reserved for issuance under the Amended and Restated 2021 Plan increased by 12,292,155 shares on January 1, 2023. The Amended and Restated 2021 Plan provides for the grant of incentive and non-statutory stock options, stock appreciation rights, restricted stock awards, restricted stock units, performance awards, and other awards to employees, directors, and non-employees. In connection with the adoption of the 2021 Plan, the Company ceased issuing awards under its 2019 Equity Incentive Plan (the “2019 Plan”). Following the closing of the Business Combination, the Company assumed the outstanding stock options under the 2019 Plan and converted such stock options into options to purchase the Company’s common stock. Such stock options will continue to be governed by the terms of the 2019 Plan and the stock option agreements thereunder, until such outstanding options are exercised or until they terminate or expire. Employee Stock Purchase Plan In August 2021, the Company adopted the 2021 Employee Stock Purchase Plan (the “ESPP”), which became effective immediately upon the closing of the Business Combination. The ESPP permits eligible employees to purchase shares of Class A common stock at a price equal to 85% of the lower of the fair market value of Class A common stock on the first day of an offering or on the date of purchase. Additionally, the number of shares of Class A common stock reserved for issuance under the ESPP will automatically increase on January 1st of each year, beginning on January 1, 2022 and continuing through and including January 1, 2031, by the lesser of (i) 1.0% of the total number of shares of Class A common stock outstanding on December 31 of the preceding year; (ii) 9,938,118 shares of Class A common stock; or (iii) a lesser number of shares of Class A common stock determined by the Board of Directors prior to the date of increase (the “ESPP Evergreen Provision”). The ESPP Evergreen Provision is calculated using the number of legally outstanding shares of common stock and includes shares, such as unvested shares pursuant to early exercised stock options, that are not considered outstanding for accounting purposes. In accordance therewith, the number of shares of Class A common stock reserved for issuance under the ESPP increased by 1,809,383 on January 1, 2023. As of December 31, 2023, the maximum number of shares authorized for issuance under the ESPP was 8,406,337, of which 7,177,705 shares remained available under the ESPP. The Company currently offers six-month offering periods, and at the end of each offering period, which occurs every six months on May 31 and November 30, employees can elect to purchase shares of the Company’s Class A common stock with contributions of up to 15% of their base pay, accumulated via payroll deductions, subject to certain limitations. During the year ended December 31, 2023, for the six-month ESPP offering periods that ended on May 31, 2023 and November 30, 2023, employees purchased 601,105 shares at a price of $2.19 per share and 627,527 shares at a price of $2.54 per share, respectively. The Company uses the Black-Scholes option pricing model to calculate the grant date fair value of each award granted under the ESPP. The following table sets forth the key assumptions and fair value results for each award granted in the Company’s six-month offering period that started on December 1, 2023: Input December 1, 2023 Stock price $ 6.30 Risk-free interest rate 5.26 % Term (in years) 0.50 Volatility 97.50 % Dividend yield 0.00 % Grant date fair value per share $ 2.62 During the years ended December 31, 2023 and 2022, the Company recognized stock-based compensation expense of $1.2 million and $0.1 million for the ESPP, respectively. There were no ESPP offerings for the year ended December 31, 2021. As of December 31, 2023, the total remaining stock-based compensation expense was $1.2 million for the ESPP, which is expected to be recognized over the current six-month offering period until May 31, 2024. Annual Equity Awards Subject to the achievement of certain performance goals established by the Company from time to time, the Company’s employees are eligible to receive an annual incentive bonus that will entitle them to an annual grant of a number of RSUs determined by dividing the annual bonus target amount by the closing price of the Company’s Class A common stock on the date of grant. The RSUs will be fully vested on the date of grant. Furthermore, all the annual equity awards are contingent and issued only upon approval by the Company’s Board of Directors or the Compensation Committee. During the years ended December 31, 2023 and 2022, the Company recognized stock-based compensation expense of $11.5 million and $9.5 million, respectively, related to these annual equity awards. There were no annual equity awards granted during the year ended December 31, 2021. Stock Options A summary of the Company’s stock option activity is as follows: Number of Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Life (Years) Aggregate Intrinsic Value (In millions) Outstanding as of January 1, 2023 5,335,974 $ 0.12 7.66 $ 9.4 Exercised (2,027,221) 0.12 7.8 Expired/forfeited (134,639) 0.12 Outstanding as of December 31, 2023 3,174,114 0.12 6.66 19.1 Exercisable as of December 31, 2023 1,346,269 $ 0.13 6.75 $ 8.1 Vested and expected to vest as of December 31, 2023 3,174,114 0.12 6.66 19.1 There were no options granted for the years ended December 31, 2023 and 2022. During the year ended December 31, 2021, the Company granted 1,277,622 incentive and non-statutory stock options under the 2019 Plan. Determination of Fair Value The assumptions used in the Black-Scholes option pricing model to estimate the fair value of the stock options granted during the year ended December 31, 2021 are provided in the following table: December 31, 2021 Risk-free interest rate: Employee stock options 0.62 % Non-employee stock options 1.08 % Expected term (in years): Employee stock options 6.32 Non-employee stock options 10.00 Expected volatility: Employee stock options 87.94 % Non-employee stock options 88.03 % Dividend yield: Employee stock options 0.00 % Non-employee stock options 0.00 % Grant date fair value per share: Employee stock options $ 13.65 Non-employee stock options $ 13.68 The Company recognized stock-based compensation expense of $2.8 million, $3.8 million and $3.9 million for stock options for the years ended December 31, 2023, 2022 and 2021, respectively. As of December 31, 2023, the total remaining stock-based compensation expense for unvested stock options was $4.9 million, which is expected to be recognized over a weighted-average period of 0.8 years. Restricted Stock Units A summary of the Company’s RSU activity is as follows: Number of Shares Weighted Average Grant Price Outstanding as of January 1, 2023 43,146,632 $ 5.72 Granted 11,864,674 3.36 Vested (7,555,232) 3.95 Forfeited (15,933,591) 6.26 Outstanding as of December 31, 2023 31,522,483 4.99 During the year ended December 31, 2023, the Company granted 998,364 RSUs under the Amended and Restated 2021 Plan, representing the quarterly equity awards for the Company’s fourth fiscal quarter of 2022. The RSUs were fully vested on the date of grant and settled in Class A common stock on a one-for-one basis. In addition, the Company granted 10,866,310 RSUs under the Amended and Restated 2021 Plan, which generally vest over a three Immediately prior to closing of the Business Combination, each of the Company’s founders was granted 20,009,224 RSUs under the 2019 Plan pursuant to the terms and conditions of the Business Combination Agreement. Considering each of the founder’s existing equity ownership and assuming the Founder Grants fully vest, it would result in each of the founders owning approximately 18% of all outstanding shares of the Total Outstanding Capitalization of the Company (as defined in the Business Combination Agreement). One-quarter of each of the Founder Grants vests upon the achievement of the earlier to occur of (i) a price-based milestone or (ii) a performance-based milestone, with a different set of such price and performance-based milestones applying to each quarter of each of the Founder Grants and so long as the achievement occurs within seven years following the closing of the Business Combination. The Company accounts for the Founder Grants as four separate tranches, with each tranche consisting of two award grants, a performance award grant and market award grant. Each tranche vests when either the market condition or performance condition is satisfied (only one condition is satisfied). The Company determined the fair value of the performance award by utilizing the trading price on the Closing Date. When the applicable performance milestone is deemed probable of being achieved, the Company will recognize compensation expense for the portion earned to date over the requisite period. For the market award, the Company determined both the fair value and derived service period using a Monte Carlo simulation model on the Closing Date. The Company will recognize compensation expense for the market award on a straight-line basis over the derived service period. If the applicable performance condition is not probable of being achieved, compensation cost for the value of the award incorporating the market condition is recognized, so long as the requisite service is provided. If the performance milestone becomes probable of being achieved, the full fair value of the award will be recognized, and any remaining expense for the market award will be canceled. The following assumptions were used to estimate the fair value, using the Monte Carlo simulation, of the market award grant: September 16, 2021 Stock price $ 9.92 Term (in years) 7 Volatility 55.00 % Risk-free interest rate 1.13 % Dividend yield 0.00 % One-quarter of each of the Founder Grants, totaling 5,002,306 shares each of Class B common stock, vested immediately prior to the Closing Date pursuant to the terms and conditions of the Business Combination Agreement. On April 14, 2022, the vested 5,002,306 shares of Class B common stock of the Company’s co-founder and former co-CEO, were cancelled. Following the separation of the officer from the Company on April 13, 2022 (the “Separation Date”), the officer’s unvested 15,006,918 shares of Class B common stock for the remaining three tranches remain outstanding and eligible for vesting upon the achievement of the milestones as described above for 15 months from the Separation Date pursuant to the original terms of the Founder Grants. On July 13, 2023, 15 months following the separation of the officer from the Company, the officer’s unvested 15,006,918 shares of Class B common stock for the remaining three tranches of the Founder Grants were forfeited. The Company reversed the previously recognized stock-compensation expense associated with these shares for $59.1 million. As of December 31, 2023, there were 15,006,918 shares of Class B common stock outstanding for the remaining Founder Grants. For the years ended December 31, 2023, 2022 and 2021, the Company recorded $49.7 million, $64.9 million and $118.1 million, respectively, of stock-based compensation expense for the amortized portion of the market award for the remaining three tranches of the outstanding Founder Grants in general and administrative expenses in the consolidated statements of operations. Of the amounts recorded during the years ended December 31, 2023, 2022 and 2021, approximately $17.3 million, $32.4 million and $9.4 million, respectively, of stock-based compensation expense associated with the forfeiture were reversed in July 2023 and recorded during the year ended December 31, 2023. For the years ended December 31, 2023, 2022 and 2021, the Company recorded $27.0 million, $22.8 million and $1.6 million of stock-based compensation expense, respectively, related to RSUs (excluding the Founder Grants). As of December 31, 2023, the total remaining stock-based compensation expense for unvested RSUs (including the remaining Founder Grants) was $128.5 million, which is expected to be recognized over a weighted-average period of 1.0 year. Restricted Stock In August 2023, the Company issued 1,985,559 shares of Class A common stock to an outside vendor to satisfy $11.0 million of the Company’s outstanding payable to that vendor. Accordingly, the Company reclassified $11.6 million, representing the grant date fair value of the award, of legal expense to stock-based compensation expense within general and administrative expenses in the consolidated statements of operations during the year ended December 31, 2023. The Company records stock-based compensation expense for stock-based compensation awards based on the fair value on the date of grant. The stock-based compensation expense is recognized ratably over the course of the requisite service period. The Company has elected to account for forfeitures as they occur and will record stock-based compensation expense assuming all stockholders will complete the requisite service period. If an employee forfeits an award because they fail to complete the requisite service period, the Company will reverse stock-based compensation expense previously recognized in the period the award is forfeited. The following table presents stock-based compensation expense included in each respective expense category in the consolidated statements of operations (in millions): Year Ended December 31, 2023 2022 2021 Research and development $ 28.9 $ 26.1 $ 3.7 General and administrative 16.3 76.7 119.9 Total stock-based compensation expense $ 45.2 $ 102.8 $ 123.6 Warrants A summary of the Company’s warrant activity is as follows: Number of Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Life (Years) Aggregate Intrinsic Value (In millions) Outstanding as of January 1, 2023 8,736,599 $ 0.01 7.84 $ 16.3 Issued 15,000,000 0.01 Exercised (2,948,352) 0.01 17.0 Outstanding as of December 31, 2023 20,788,247 0.01 4.48 127.4 Vested as of December 31, 2023 2,839,893 $ 0.01 2.17 $ 17.4 United Airlines On January 29, 2021, the Company entered into the United Purchase Agreement, United Collaboration Agreement, and United Warrant Agreement. Under the terms of the United Purchase Agreement, United has a conditional purchase order for up to 200 of the Company’s aircraft, with an option to purchase an additional 100 aircraft. Those purchases are conditioned upon the Company meeting certain conditions that include, but are not limited to, the certification of the Company’s aircraft by the FAA and further negotiation and reaching of mutual agreement on certain material terms related to the purchases. The Company issued 14,741,764 warrants to United to purchase shares of the Company’s Class A common stock. Each warrant provides United with the right to purchase one share of the Company’s Class A common stock at an exercise price of $0.01 per share. The warrants were initially expected to vest in four installments in accordance with the following milestones: the execution of the United Purchase Agreement and the United Collaboration Agreement, the completion of the Business Combination, the certification of the aircraft by the FAA, and the sale of aircraft to United. On August 9, 2022, the Company entered into Amendment No. 1 to the United Purchase Agreement (the “Amended United Purchase Agreement”) and Amendment No. 1 to the United Warrant Agreement (the “Amended United Warrant Agreement”). In association with the Amended United Purchase Agreement, the Company received a $10.0 million pre-delivery payment from United for 100 of the Company’s aircraft (the “Pre-Delivery Payment”), which was recognized as a contract liability in other long-term liabilities in the Company’s consolidated balance sheets. Pursuant to the Amended United Warrant Agreement, the vesting condition of the fourth milestone of the United Warrant Agreement was modified, and the warrants now vest in four installments in accordance with the following sub-milestones: (i) 737,088 warrants vested upon receipt by the Company of the Pre-Delivery Payment on August 9, 2022; (ii) 2,211,264 warrants vested on February 9, 2023 upon the six-month anniversary of the amendment date; (iii) 3,685.45 warrants shall vest upon the acceptance and delivery of each of the Company’s 160 aircraft; and (iv) 22,112.65 warrants shall vest upon the acceptance and delivery of each of the Company’s 40 aircraft. The Company accounts for the Amended United Purchase Agreement and the United Collaboration Agreement under ASC 606, Revenue from Contracts with Customers . The Company identified the sale of each aircraft ordered by United as a separate performance obligation in the contract. As the performance obligations have not been satisfied, the Company has not recognized any revenue as of December 31, 2023. With respect to the warrant vesting milestones outlined above, the Company accounts for them as consideration payable to a customer under ASC 606 related to the future purchase of aircraft by United. The Company determined that the warrants are classified as equity awards based on the criteria of ASC 480, Distinguishing Liabilities from Equity and ASC 718, Compensation — Stock Compensation . Pursuant to ASC 718, the Company measured the grant date fair value of the warrants to be recognized upon the achievement of each of the original four milestones and the vesting of the related warrants. On January 29, 2021, a valuation of the Company’s common stock was performed, valuing the Company’s common stock at $13.35 per share. The value of the common stock was determined using a hybrid approach of the OPM and PWERM, with the PWERM weighted at 80% primarily based on management’s expectation of the planned merger as described in Note 1 and the OPM weighted at 20% due to uncertainties in the timing of other possible scenarios. The Company used the OPM to allocate value in a stay private scenario. Given the $0.01 exercise price, each warrant also had a fair value of $13.35 at the grant date. For the first milestone, issuance of warrants in conjunction with the execution of the United Purchase Agreement and the United Collaboration Agreement, the Company recorded the grant date fair value of the respective warrant tranche at the vesting date upon satisfaction of the milestone, and the related costs were recorded in other warrant expense due to the absence of historical or probable future revenue. For the second milestone, the completion of the Business Combination transaction, the related costs were also recorded in other warrant expense due to the absence of historical or probable future revenue. For the third milestone, the certification of the aircraft by the FAA, the Company will assess whether it is probable that the award will vest at the end of every reporting period. If and when the award is deemed probable of vesting, the Company will begin capitalizing the grant date fair value of the associated warrants as an asset through the vesting date and subsequently amortize the asset as a reduction to revenue as it sells the new aircraft to United. For the original fourth milestone, the sale of aircraft to United, the Company was initially expected to record the cost associated with the vesting of each portion of warrants within this milestone as a reduction of the transaction price as revenue is recognized for each sale of the aircraft. In connection with the Amended United Warrant Agreement, the Company evaluated the accounting implications associated with the amendment to the fourth milestone in accordance with ASC 606 and ASC 718. For the first sub-milestone, the receipt of the Pre-Delivery Payment, the Company accounted for it as a modification under ASC 718 and recorded the modification date fair value of the associated warrants in other warrant expense upon satisfaction of the sub-milestone on August 9, 2022. For the second sub-milestone, the vesting of warrants on February 9, 2023, the Company accounted for it as a modification under ASC 718 and recorded the modification date fair value of the associated warrants in other warrant expense on a straight-line basis over six months following the amendment date. The modification date fair value of each warrant associated with the first and second sub-milestones was determined to be $4.37, which was the closing price of the Company’s Class A common stock on the modification date. For the third and fourth sub-milestones, the sale of 160 aircraft and 40 aircraft, respectively, the Company determined that the amendment does not represent a modification under ASC 718. The Company will record the cost associated with the vesting of each portion of the associated warrants as a reduction of the transaction price based on the original grant date fair value as revenue is recognized for each sale of the aircraft. For the year ended December 31, 2023, the Company recorded $2.1 million in other warrant expense in the consolidated statements of operations related to the second sub-milestone under the fourth milestone, and a total of 2,211,264 warrants vested from achievement of this milestone. For the year ended December 31, 2022, the Company recorded $10.8 million in other warrant expense in the consolidated statements of operations related to the first two sub-milestones under the fourth milestone, and a total of 737,088 warrants vested from achievement of the first sub-milestone under the fourth milestone. In August 2023, the Company issued 2,942,778 shares of Class A common stock to United, who cashless net exercised 2,948,352 warrants related to the achievement of the first two sub-milestones under the fourth milestone. For the year ended December 31, 2021, the Company recorded $117.3 million in other warrant expense in the consolidated statements of operations related to the achievement of the first two milestones. A total of 8,845,058 warrants vested from achievement of the first two milestones and were exercised during the year ended December 31, 2021. Stellantis N.V. On January 3, 2023, the Company entered into a manufacturing and collaboration agreement with Stellantis N.V. (“Stellantis”), pursuant to which the Company and Stellantis will collaborate on the development and implementation of the Company’s manufacturing operations for the production of its eVTOL aircraft products (the “Stellantis Collaboration Agreement”). In connection with the Stellantis Collaboration Agreement, the Company entered into a forward purchase agreement (as amended, the “Stellantis Forward Purchase Agreement”) and a warrant agreement (the “Stellantis Warrant Agreement”) with Stellantis on January 3, 2023. Under the terms of the Stellantis Forward Purchase Agreement, the Company may elect, in the Company’s sole discretion, to issue and sell to Stellantis up to $150.0 million of shares of the Company’s Class A common stock, following the satisfaction of certain Milestones (as defined in the Stellantis Forward Purchase Agreement) and pursuant to the terms and conditions of the Stellantis Forward Purchase Agreement. As any issuance of Class A common stock by the Company to Stellantis pursuant to the Stellantis Forward Purchase Agreement is at the election of the Company, the Company will recognize any share issuance at the time it elects to issue and sell shares to Stellantis. Under the terms of the Stellantis Warrant Agreement, Stellantis is entitled to purchase up to 15.0 million shares of the Company’s Class A common stock, at an exercise price of $0.01 per share (the “Stellantis Warrant”). The Stellantis Warrant will vest and become exercisable in three equal tranches upon 12, 24 and 36 months of the grant date, provided that (i) Stellantis has performed certain undertakings set forth in the Stellantis Collaboration Agreement and/or (ii) the VWAP (as defined in the Stellantis Warrant Agreement) for the Class A common stock exceeding certain specified amounts. Pursuant to the terms and conditions of the Stellantis Collaboration Agreement, Stellantis is deemed to have performed the undertakings if the Stellantis Collaboration Agreement has not been terminated by the Company as of the specified vesting date for each tranche. As the Company is currently in pre-revenue stage and is not generating any revenue from the Stellantis Collaboration Agreement, all costs incurred with third parties are recorded based on the nature of the costs incurred. The Company accounts for the warrant in accordance with the provisions of ASC 718. The grant date fair value of each warrant was determined to be $1.93, which was the closing price of the Company’s Class A common stock on January 3, 2023. For each tranche of the warrant, the Company will recognize compensation costs as the related services are received from Stellantis on a straight-line basis over the associated service period. During the year ended December 31, 2023, the Company recorded $17.5 million of R&D expense in the consolidated statements of operations in connection with the Stellantis Collaboration Agreement. On June 23, 2023, the Company issued 6,337,039 shares of Class A common stock to Stellantis at a price of $3.94506 per share in connection with the first milestone under the Stellantis Forward Purchase Agreement and received approximately $25.0 million in gross proceeds. The Company recognized the issued shares at a fair value of $3.38 per share, which was the closing price of the Company’s Class A common stock on June 23, 2023, and recognized a gain of $3.6 million within other (expense) income, net in the consolidated statements of operations during the year ended December 31, 2023, to account for the difference between the amount of cash proceeds and the fair value of the issued shares. On August 10, 2023, Stellantis waived certain conditions provided for in the Stellantis Forward Purchase Agreement relating to the Company’s actual achievement pursuant to Milestone 2 (as defined in the Stellantis Forward Purchase Agreement). In connection with this waiver, the Company submitted an election notice to draw down upon the $70.0 million applicable to Milestone 2, which equals 12,313,234 shares of the Company’s Class A common stock. This drawdown was completed on October 16, 2023. FCA US LLC On November 6, 2020, the Company entered into a collaboration agreement with FCA US LLC (“FCA”) (the “FCA Collaboration Agreement”), in which both parties agreed to work together to complete a series of fixed duration collaboration projects related to the Company’s ongoing efforts to design, develop, and bring up production capabilities for its aircraft. In conjunction with the FCA Collaboration Agreement, the Company issued a warrant to FCA on November 6, 2020, in which FCA has the right to purchase up to 1,671,202 shares of the Company’s Class A common stock at an exercise price of $0.01 per share. The Company performed a valuation and determined each warrant had a fair value of $0.15 per share at the grant date. Shares under the warrant vest based on the completion of specific aircraft development milestones identified under the FCA Collaboration Agreement. As the Company is currently in pre-revenue stage and is not generating any revenue from the FCA Collaboration Agreement, all costs incurred with third parties are recorded based on the nature of the cost incurred. The Company accounts for the warrant in accordance with ASC 718. The Company assessed whether it was probable that the award vested for each of the seven milestones at the end of every reporting period. If and when the award was deemed probable of vesting, the Company recognized compensation expense for the portion of the grant determined probable of vesting on a straight-line basis over the duration of each milestone. If services had been provided by FCA prior to management determining the milestone was probable of being achieved, a cumulative catch-up adjustment was recorded for services performed in prior periods. During the years ended December 31, 2022 and 2021, the Company recorded $0.1 million and $0.2 million of R&D expense, respectively, in the consolidated statements of operations related to the completion of certain milestones. As of December 31, 2022, all seven milestones have been completed, amounting to 1,671,202 shares that have vested. FCA Italy S.p.A. On July 19, 2021, the Company entered into a manufacturing consulting agreement with an affiliate of FCA, FCA Italy S.p.A. (“FCA Italy”) (the “Manufacturing Consulting Agreement”), in which both parties agreed to work together to complete a series of fixed duration projects to develop manufacturing and production processes in connection with the Company’s ongoing efforts to bring up production capabilities for its aircraft. In conjunction with the Manufacturing Consulting Agreement, the Company issued a warrant to FCA Italy, in which FCA Italy has the right to purchase up to 1,077,024 shares of the Company’s Class A common stock at an exercise price of $0.01 per share. The Company performed a valuation and determined each warrant had a fair value of $8.98 per share at the grant date. The shares underlying the warrant vest in two equal installments in accordance with two time-based milestones. The Company accounts for the warrant in accordance with ASC 718. The Company recognized compensation cost for half of the shares that were fully vested upon execution of the Manufacturing Consulting Agreement. The Company recognized compensation cost for the remaining half of the warrant as the related services were received from FCA Italy on a straight-line basis over the service period of 12 months. During the year ended December 31, 2022, the Company recorded $2.8 million of R&D expense in the consolidated statements of operations related to services received for the second milestone. During the year ended December 31, 2021, the Company recorded $6.8 million of R&D expense in the consolidated statements of operations related to the achievement of the first milestone and services received for the second milestone. As of December 31, 2022, both of the milestones have been completed, amounting to 1,077,024 shares that have vested.

Income Taxes

Income Taxes	12 Months Ended
Income Taxes	Dec. 31, 2023
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company's loss before income taxes consisted of the following (in millions): Year Ended December 31, 2023 2022 2021 United States $ (458.7) $ (317.3) $ (347.8) International 1.3 — — Total $ (457.4) $ (317.3) $ (347.8) The Company recognized foreign current income tax provision of $0.5 million during the year ended December 31, 2023. The Company did not recognize any current income tax provision during the years ended December 31, 2022 and 2021. The Company did not record any deferred income tax provision for the years ended December 31, 2023, 2022 and 2021. The related increase in the deferred tax assets was offset by the increase in valuation allowance. A reconciliation of the Company’s effective income tax rate to the expected income tax rate, computed by applying the federal statutory income tax rate of 21% to the Company’s loss before income taxes, is as follows: Year Ended December 31, 2023 2022 2021 Federal income tax (benefit) at statutory tax rate 21.0 % 21.0 % 21.0 % State and local income taxes (net of federal benefit) (2.7) % 2.5 % 2.6 % Nondeductible expenses (0.1) % (0.2) % (0.2) % Warrant expense (1.6) % 0.8 % (6.5) % Nondeductible officers’ compensation 0.1 % (4.7) % (6.9) % Other 0.0 % (0.7) % 0.2 % Credits 4.4 % 4.9 % 1.3 % Change in valuation allowance (21.2) % (23.6) % (11.5) % Effective tax rate (0.1) % 0.0 % 0.0 % Differences between the state statutory rate and state effective tax rate for the year ended December 31, 2023 primarily relate to the limitations imposed on certain share-based compensation under Section 162(m), R&D tax credits and an increase in the valuation allowance. The tax effects of temporary differences that give rise to significant portions of the deferred tax assets and deferred tax liabilities are provided below (in millions): As of December 31, 2023 2022 Deferred tax assets: Net operating loss carryforwards $ 84.1 $ 43.4 Accrued expenses 12.4 1.5 Operating lease liabilities 3.5 3.3 Stock-based compensation 1.9 3.7 Warrants 6.0 2.5 Capitalized R&D expenses 77.8 51.7 Credits 41.7 21.1 Start-up costs 3.8 4.7 Other 0.7 0.9 Gross deferred tax assets 231.9 132.8 Less: valuation allowance (226.3) (129.7) Deferred tax assets, net of valuation allowance 5.6 3.1 Deferred tax liabilities: Depreciation and amortization (3.7) — Right-of-use assets (1.9) (3.1) Total deferred tax liabilities (5.6) (3.1) Total net deferred tax assets $ — $ — In assessing the realizability of deferred tax assets, management considers whether it is more-likely-than-not that some portion or all of the deferred tax assets will not be realized. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the period in which those temporary differences become deductible. Based upon the analysis of federal and state deferred tax balances and future tax projections and the Company’s lack of taxable income in the carryback period, the Company recorded a valuation allowance of $226.3 million against the federal and state deferred tax assets. The valuation allowance increased by $96.6 million, $82.6 million and $39.9 million during the years ended December 31, 2023, 2022 and 2021, respectively. On August 16, 2022, the U.S. government enacted the Inflation Reduction Act of 2022. The Company does not currently expect the Inflation Reduction Act to impact its estimated effective tax rate due to a full valuation allowance against deferred tax assets. As of December 31, 2023 and 2022, the Company has U.S. federal net operating loss (“NOL”) carryforwards of $389.9 million and $173.5 million, respectively, which can be carried forward indefinitely. As of December 31, 2023 and 2022, the Company has state NOL carryforwards of $40.5 million and $120.1 million, respectively, which will both begin to expire in 2038. In the ordinary course of its business, the Company incurs costs that, for tax purposes, are determined to be qualified R&D expenditures within the meaning of IRC §41 and are, therefore, eligible for the Increasing Research Activities credit under IRC §41. The U.S. federal R&D tax credit carryforward is $31.4 million and $14.9 million for December 31, 2023 and 2022, respectively. The U.S. federal R&D tax credit carryforward begins to expire in 2039. The state R&D tax credit carryforward is $15.7 million and $9.3 million for December 31, 2023 and 2022, respectively, which can be carried forward indefinitely. The following table summarizes the activity related to the Company’s unrecognized tax benefits during the years ended December 31, 2023, 2022 and 2021 (in millions): Balance as of December 31, 2020 $ 2.0 Increases related to current year tax positions 0.3 Decreases based on tax positions related to prior years (2.0) Balance as of December 31, 2021 0.3 Increases related to current year tax positions 1.2 Balance as of December 31, 2022 1.5 Increases related to current year tax positions 0.5 Balance as of December 31, 2023 $ 2.0 The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate as of December 31, 2023 and 2022 is zero due to the valuation allowance that would otherwise be recorded on the deferred tax asset associated with the recognized position. During the years ended December 31, 2023, 2022 and 2021, the Company recognized no interest and penalties related to uncertain tax positions. It is not expected that there will be a significant change in uncertain tax positions in the next 12 months. In accordance with Section 382 and Section 383 of the Internal Revenue Code of 1986, as amended (the “Code”), a corporation that undergoes an “ownership change” (generally defined as a cumulative change of more than 50% in the equity ownership of certain stockholders over a rolling three-year period) is subject to limitations on its ability to utilize its pre-change NOLs and R&D tax credits to offset post-change taxable income and post-change tax liabilities, respectively. The Company’s existing NOLs and R&D credits may be subject to limitations arising from previous ownership changes, and the ability to utilize NOLs could be further limited by Section 382 and Section 383 of the Code. In addition, future changes in the Company’s stock ownership, some of which may be outside of the Company’s control, could result in an ownership change under Section 382 and Section 383 of the Code. The amount of such limitations, if any, has not been determined. The Company is subject to taxation and files income tax returns with the U.S. federal government and the states of California and Florida. The tax years ended December 31, 2018 through December 31, 2023 remain open to examination for federal purposes, and the tax years ended December 31, 2018 through December 31, 2023 remain open to examination for state purposes. In addition, the utilization of NOL and R&D credit carryforwards is subject to federal and state review for the periods in which those net losses were incurred. The Company is not under audit by any tax jurisdictions at this time.

Liability Classified Warrants

Liability Classified Warrants	12 Months Ended
Liability Classified Warrants	Dec. 31, 2023
Warrants and Rights Note Disclosure [Abstract]
Liability Classified Warrants	Liability Classified Warrants As of December 31, 2023, there were 17,398,947 public w arrants outstanding. Public warrants may only be exercised for a whole number of shares. No fractional shares are issued upon exercise of the public warrants. The public warrants became exercisable on October 30, 2021, 12 months after the closing of the initial public offering of Atlas. The public warrants will expire five years from the consummation of the Business Combination or earlier upon redemption or liquidation. Once the public warrants become exercisable, the Company may redeem the public warrants for redemption: • in whole and not in part; • at a price of $0.01 per public warrant; • upon not less than 30 days’ prior written notice of redemption to each warrant holder; and • if, and only if, the closing price of the Class A common stock equals or exceeds $18.00 per share (as adjusted for stock splits, stock dividends, reorganizations, recapitalizations and the like) for any 20 trading days within a 30-trading day period commencing after the warrants become exercisable and ending three If and when the warrants become redeemable by the Company, the Company may exercise its redemption right even if the Company is unable to register or qualify the underlying securities for sale under all applicable state securities laws. Each public warrant entitles the registered holder to purchase one share of Class A common stock at a price of $11.50 per share. The exercise price and number of Class A common stock issuable upon exercise of the public warrants may be adjusted in certain circumstances including in the event of a share dividend, extraordinary dividend or recapitalization, reorganization, merger, or consolidation. The public warrants will not be adjusted for issuances of Class A common stock at a price below its exercise price. Additionally, in no event will the Company be required to net cash settle the public warrants. As of December 31, 2023, there were 8,000,000 private placement warrants outstanding. The private placement warrants are identical to the public warrants underlying the shares sold in the initial public offering of Atlas, except that the private placement warrants and the shares of Class A common stock issuable upon the exercise of the private placement warrants became transferable, assignable, and salable on October 16, 2021, 30 days after the completion of the Business Combination, subject to certain limited exceptions. Additionally, the private placement warrants will be exercisable on a cashless basis and will be non-redeemable so long as they are held by the initial purchasers or their permitted transferees. If the private placement warrants are held by someone other than the initial purchasers or their permitted transferees, the private placement warrants will be redeemable by the Company and exercisable by such holders on the same basis as the public warrants.

Subsequent Events

Subsequent Events	12 Months Ended
Subsequent Events	Dec. 31, 2023
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events The Company evaluated subsequent events and transactions that occurred after the balance sheet date through the date of the issuance of these consolidated financial statements. The Company did not identify any subsequent events that would have required adjustment or disclosure in the consolidated financial statements.

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Millions	12 Months Ended
Pay vs Performance Disclosure - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Pay vs Performance Disclosure
Net loss	$ (457.9)	$ (317.3)	$ (347.8)

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
Insider Trading Arrangements	Dec. 31, 2023
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
Summary of Significant Accounting Policies (Policies)	Dec. 31, 2023
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying consolidated financial statements have been prepared in conformity with U.S. GAAP and include the accounts of the Company.
Use of Estimates	Use of Estimates The preparation of the consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent liabilities at the date of the consolidated financial statements and the reported amounts of expenses during the reporting period. On an ongoing basis, management evaluates its estimates, including those related to the: (i) realization of deferred tax assets and estimates of tax liabilities, (ii) fair value of debt, (iii) fair value of share-based payments, (iv) valuation of leased assets and liabilities, and (v) estimated useful lives of long-lived assets. These estimates are based on historical data and experience, as well as various other factors that management believes to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying value of assets and liabilities that are not readily apparent from other sources. Such estimates often require the selection of appropriate valuation methodologies and models and may involve significant judgment in evaluating ranges of assumptions and financial inputs. Actual results may differ from those estimates under different assumptions, financial inputs, or circumstances.
Cash, Cash Equivalents, and Restricted Cash	Cash consists of cash on deposit with financial institutions. Cash equivalents consist of short-term, highly liquid financial instruments that are readily convertible to cash and have maturities of three months or less from the date of purchase.
Short-Term Investments	Short-Term Investments The Company had short-term investments in marketable securities with original maturities of less than one year, including U.S. Treasury securities, corporate debt securities and commercial paper. The Company classifies its marketable securities as available-for-sale at the time of purchase and reevaluates such classification at each balance sheet date. These marketable securities are carried at fair value, and unrealized gains and losses are recorded in other comprehensive loss in the consolidated statements of comprehensive loss, which is reflected as a component of stockholders’ equity. These marketable securities are assessed as to whether those with unrealized loss positions are other than temporarily impaired. The Company considers impairments to be other than temporary if they are related to deterioration in credit risk or if it is likely the securities will be sold before the recovery of their cost basis. If the impairment is deemed other than temporary, the security is written down to its fair value and a loss is recognized in other (expense) income, net. Realized gains and losses from the sale of marketable securities and from declines in value deemed to be other than temporary are determined based on the specific identification method and recognized in other (expense) income, net in the consolidated statements of operations.
Fair Value Measurements	Fair Value Measurements The Company applies the provisions of Accounting Standards Codification (“ASC”) 820, Fair Value Measurement, which defines a single authoritative definition of fair value, sets out a framework for measuring fair value, and expands on required disclosures about fair value measurements. The provisions of ASC 820 relate to financial assets and liabilities as well as other assets and liabilities carried at fair value on a recurring and nonrecurring basis. The standard clarifies that fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, the standard establishes a three-tier value hierarchy, which prioritizes the inputs used in measuring fair value as follows: Level 1 Unadjusted quoted prices in active markets for identical assets or liabilities accessible to the reporting entity at the measurement date. Level 2 Other than quoted prices included in Level 1 inputs that are observable for the asset or liability, either directly or indirectly, for substantially the full term of the asset or liability. Level 3 Unobservable inputs for the asset or liability used to measure fair value to the extent that observable inputs are not available, thereby allowing for situations in which there is little, if any, market activity for the asset or liability at the measurement date. The carrying amounts of the Company’s cash, accounts payable, accrued compensation, and accrued liabilities approximate their fair values due to the short-term nature of these instruments. Cash Equivalents The Company’s cash equivalents consist of short-term, highly liquid financial instruments that are readily convertible to cash and have maturities of three months or less from the date of purchase. The Company classifies its money market funds as Level 1, because they are valued based on quoted market prices in active markets. Short-Term Investments The Company’s short-term investments consisted of high quality, investment grade marketable securities and were classified as available-for-sale. The Company classifies its investments in U.S. Treasury securities as Level 1, because they are valued using quoted market prices in active markets. The Company classifies its investments in corporate debt securities and commercial paper as Level 2, because they are valued using inputs other than quoted prices which are directly or indirectly observable in the market, including readily available pricing sources for the identical underlying security which may not be actively traded. Public Warrants Private Placement Warrants The Company utilizes a Monte Carlo simulation model for the private placement warrants at each reporting period, with changes in fair value recognized in the consolidated statements of operations. The estimated fair value of the private placement warrant liability is determined using Level 3 inputs. Inherent in a Monte Carlo simulation model are assumptions related to expected share-price volatility, expected life, risk-free interest rate, and dividend yield. Financial Instruments Not Recorded at Fair Value on a Recurring Basis Certain financial instruments, including debt, are not measured at fair value on a recurring basis in the consolidated balance sheets. The fair value of debt as of December 31, 2023 approximates its carrying value (Level 2). Refer to Note 7 - Notes Payable for additional information. Assets and Liabilities Recorded at Fair Value on a Non-Recurring Basis Certain assets and liabilities are subject to measurement at fair value on a non-recurring basis if there are indicators of impairment or if they are deemed to be impaired as a result of an impairment review.
Intangible Assets, Net	Intangible Assets, Net Intangible assets consist solely of domain names and are recorded at cost, net of accumulated amortization, and if applicable, impairment charges. Amortization of domain names is provided over a 15-year estimated useful life on a straight-line basis or based on the pattern in which economic benefits are consumed, if reliably determinable. The Company reviews intangible assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. The Company has analyzed a variety of factors to determine if any circumstance could trigger an impairment loss, and, at this time and based on the information presently known, no event has occurred and indicated that it is more likely than not that an impairment loss has been incurred. Therefore, the Company did not record any impairment charges for its intangible assets for the years ended December 31, 2023, 2022 and 2021.
Property and Equipment, Net	Property and Equipment, Net Property and equipment are stated at historical cost less accumulated depreciation. Expenditures for major renewals and betterment are capitalized, while minor replacements, maintenance, and repairs, which do not extend the asset lives, are charged to operations as incurred. Upon sale or disposition, the cost and related accumulated depreciation is removed from the accounts, and any difference between the selling price and net carrying amount is recorded as a gain or loss in the consolidated statements of operations.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets The Company reviews its long-lived assets, consisting primarily of property and equipment, for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable. Such triggering events or changes in circumstances may include: a significant decrease in the market price of a long-lived asset, a significant adverse change in the extent or manner in which a long-lived asset is being or intended to be used, a significant adverse change in legal factors or in the business climate, the impact of competition or other factors that could affect the value of a long-lived asset, a significant adverse deterioration in the amount of revenue or cash flows expected to be generated from an asset group, an accumulation of costs significantly in excess of the amount originally expected for the acquisition or development of a long-lived asset, current or future operating or cash flow losses that demonstrate continuing losses associated with the use of a long-lived asset, or a current expectation that, more likely than not, a long-lived asset will be sold or otherwise disposed of significantly before the end of its previously estimated useful life. The Company performs impairment testing at the asset group level that represents the lowest level for which identifiable cash flows are largely independent of the cash flows of other assets and liabilities. Recoverability of these assets is determined by comparing the forecasted undiscounted cash flows attributable to such assets including any cash flows upon their eventual disposition to their carrying value. If the carrying value of the assets exceeds the forecasted undiscounted cash flows, then the assets are written down to their fair value. The Company did not identify any events or changes in circumstances that would indicate that the Company’s long-lived assets may be impaired and therefore determined there was no impairment of long-lived assets during all periods presented.
Cloud Computing Arrangements	Cloud Computing Arrangements The Company capitalizes certain implementation costs incurred in the application development stage of projects related to its cloud computing arrangements that are service contracts. Capitalized implementation costs are recognized in other long-term assets in the consolidated balance sheets and amortized on a straight-line basis over the fixed, noncancellable term of the
Contract Liabilities	Contract Liabilities The Company records contract liabilities related to differences between the timing of cash receipts from the customer and the recognition of revenue. As of December 31, 2023 and 2022, the Company’s contract liability balances were $10.8 million and $10.0 million, respectively, and recorded in other long-term liabilities in the Company’s consolidated balance sheets. As of December 31, 2023, the Company’s contract liabilities consisted of a $10.0 million pre-delivery payment received from United Airlines, Inc. (“United”) under the terms of the Amended United Purchase Agreement (defined below) (see Note 10 - Stock-Based Compensation), and a $0.8 million installment payment received under a contract order with the United States Air Force for the design, development, and ground test of the Company’s production aircraft, Midnight. As of December 31, 2022, the Company’s contract liabilities consisted of the $10.0 million pre-delivery payment received from United, as discussed above. No revenues were recognized during the years ended December 31, 2023, 2022 and 2021.
Research and Development	Research and Development Research and development (“R&D”) costs are expensed as incurred and are primarily comprised of personnel-related costs including salaries, bonuses, benefits, and stock-based compensation for employees focused on R&D activities, costs associated with building prototype aircraft, other related costs, depreciation, and an allocation of general overhead. R&D efforts focus on the design and development of the Company’s eVTOL aircraft, including certain of the systems that are used in it.
General and Administrative	General and Administrative
Other Warrant Expense	Other Warrant Expense
Stock-Based Compensation	Stock-Based Compensation The Company’s stock-based compensation awards consist of options granted to employees and non-employees and RSUs granted to employees, directors, and non-employees that convert into shares of the Company’s Class A common stock upon vesting. The Company recognizes stock-based compensation expense in accordance with the provisions of ASC 718, Compensation - Stock Compensation . ASC 718 requires the measurement and recognition of compensation expense for all stock-based compensation awards made to employees, directors, and non-employees to be based on the grant date fair values of the awards. The Company estimates the fair value of stock options using the Black-Scholes option-pricing model. The value of the award is recognized as expense over the requisite service period on a straight-line basis. Determining the grant date fair value of the awards using the Black-Scholes option-pricing model requires management to make assumptions and judgments, including but not limited to the following: Expected term — The estimate of the expected term of employee awards is determined in accordance with the simplified method, which estimates the term based on an averaging of the vesting period and contractual term of the option grant. The Company uses the contractual term for non-employee awards. Expected volatility — Since the Company does not have sufficient historical data on the volatility of its common stock, the expected volatility used is based on the volatility of similar entities (referred to as “guideline companies”) for a period consistent with the expected term of the award. Risk-free interest rate — The risk-free interest rate used to value awards is based on the United States Treasury yield in effect at the time of grant for a period consistent with the expected term of the award. Dividend yield — The Company has never declared or paid any cash dividends and does not presently plan to pay cash dividends in the foreseeable future. Forfeiture rate — The Company has elected to account for forfeitures as they occur and will record stock-based compensation expense assuming all option holders will complete the requisite service period. If an employee forfeits an award because they fail to complete the requisite service period, the Company will reverse stock-based compensation expense previously recognized in the period the award is forfeited. The Company has not issued any stock options since the closing of the Business Combination. Fair Value of Common Stock The Company’s Board of Directors grants stock options with exercise prices equal to the fair value of the Company’s common stock on the date of grant. Prior to the closing of the Business Combination, the Company determined the fair value of its common stock at the time of the grant of stock options in accordance with the American Institute of Certified Public Accountants (“AICPA”) Accounting and Valuation Guide: Valuation of Privately-Held-Company Equity Securities Issued as Compensation (the “AICPA Practice Aid”). The Company determined the fair value of its common stock based on a variety of factors including, but not limited to (i) the results of contemporaneous independent third-party valuations of the Company’s common stock and the prices, rights, preferences and privileges of the Company’s redeemable convertible preferred stock relative to those of the Company’s common stock; (ii) the lack of marketability of the Company’s common stock; (iii) actual operating and financial results; (iv) current business conditions and projections; (v) the likelihood of achieving a liquidity event, such as an IPO or sale of the Company, given prevailing market conditions; and (vi) precedent transactions involving the Company’s shares. As provided in the AICPA Practice Aid, there are several approaches for setting the value of an enterprise and various methodologies for allocating the value of an enterprise to its outstanding equity. The Company determined the fair value of equity awards using a combination of the market and income approach. Within the market approach, the guideline public company method was used, which employs the use of ratios developed from the market price of traded shares from publicly traded companies considered reasonably similar to the Company. Under the income approach, the enterprise value was estimated using the discounted cash flow method, which involves estimating the future cash flows of a business for a discrete period and discounting them to their present value. In allocating enterprise value to the Company’s outstanding equity, the Company applied a hybrid approach, which consisted of the option pricing method (“OPM”) and probability-weighted expected return method (“PWERM”). The OPM treats securities, including debt, common and preferred stock, as call options on the enterprise’s value, with exercise prices based on the securities’ respective liquidation preferences and conversion values. The PWERM estimates the fair market value of the common stock based on an analysis of future values for the enterprise assuming various exit scenarios, such as IPO, merger or sale, staying private, and liquidation. Since there was no active market for the Company’s common stock, the Company also applied a discount for lack of marketability for both OPM and PWERM scenarios. In conducting the valuations, the Company considered all objective and subjective factors that the Company believed to be relevant in the valuation conducted, including management’s best estimate of the Company’s business condition, and prospects and operating performance at the valuation dates. There are significant judgments and estimates inherent in these valuations. Since the closing of the Business Combination, the fair value of the Company’s common stock is based on the closing price of the Company’s Class A common stock, as quoted on the NYSE, on the date of grant.
Leases	Leases The Company accounts for leases in accordance with ASC 842, Leases , and determines if an arrangement is a lease at its inception. Right-of-use (“ROU”) assets and liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term. The Company uses its estimated incremental borrowing rate in determining the present value of lease payments considering the term of the lease, which is derived from information available at the lease commencement date. The incremental borrowing rate is the rate of interest the Company would have to pay to borrow, on a collateralized basis, an amount equal to the lease payments for a term similar to the lease term in a similar economic environment as the lease. The lease term includes renewal options when it is reasonably certain that the option will be exercised and excludes termination options. To the extent that the Company’s agreements have variable lease payments, the Company includes variable lease payments that depend on an index or a rate and excludes those that depend on facts or circumstances occurring after the commencement date, other than the passage of time. Lease expense for leases is recognized on a straight-line basis over the lease term. The Company has elected not to recognize ROU assets and lease liabilities that arise from short-term (12 months or less) leases for any class of underlying asset. In addition, the Company has elected as an accounting policy, the practical expedient to not separate lease and non-lease components within a contract and instead treat it as a single lease component. Operating leases are included in ROU assets, current portion of lease liabilities, and lease liabilities, net of current portion in the Company’s consolidated balance sheets.
Income Taxes	Income Taxes The Company accounts for its income taxes using the asset and liability method whereby deferred tax assets and liabilities are determined based on temporary differences between the basis used for financial reporting and income tax reporting purposes. Deferred income taxes are provided based on the enacted tax rates in effect at the time such temporary differences are expected to reverse. A valuation allowance is provided for deferred tax assets if it is more-likely-than-not that the Company will not realize those tax assets through future operations. Significant judgment is applied when assessing the need for valuation allowances and includes the evaluation of historical income (loss) adjusted for the effects of non-recurring items. Areas of estimation include consideration of future taxable income. The Company has placed a full valuation allowance against its federal and state deferred tax assets since the recovery of the assets is uncertain. Should a change in circumstances lead to a change in judgment about the utilization of deferred tax assets in future years, the adjustment related to valuation allowances would be reported as an increase to income. The Company utilizes the guidance in ASC 740-10, Income Taxes , to account for uncertain tax positions. ASC 740-10 contains a two-step approach to recognizing and measuring uncertain tax positions. The first step is to evaluate the tax position for recognition by determining if the weight of available evidence indicates it is more-likely-than-not that the positions will be sustained on audit, including resolution of related appeals or litigation processes, if any. The second step is to measure the tax benefit as the largest amount which is more-likely-than-not of being realized and effectively settled. An uncertain income tax position will not be recognized if it has less than a 50% likelihood of being sustained. The Company considers many factors when evaluating and estimating its tax positions and tax benefits, which may require periodic adjustments and which may not accurately forecast actual outcomes. The Company’s policy is to recognize interest and penalties related to uncertain tax positions, if any, in the income tax provision.
Net Loss Per Share	Net Loss Per Share Basic net loss per share is calculated by dividing net loss attributable to common stockholders by the weighted-average number of common shares outstanding. For all periods presented, the calculation of basic net loss per share excludes shares issued upon the early exercise of stock options where the vesting conditions have not been satisfied. Common stock purchased pursuant to an early exercise of stock options is not deemed to be outstanding for accounting purposes until those shares vest. The Company also excludes unvested shares subject to repurchase in the number of shares outstanding in the consolidated balance sheets and statements of stockholders’ equity. Because the Company reported net losses for all periods presented, diluted loss per share is the same as basic loss per share. Contingently issuable shares, including equity awards with performance conditions, are considered outstanding common shares and included in the computation of basic net loss per share as of the date that all necessary conditions to earn the awards have been satisfied. Prior to the end of the contingency period, the number of contingently issuable shares included in diluted net loss per share is based on the number of shares, if any, that would be issuable under the terms of the arrangement at the end of the reporting period. Because the Company reported net losses for all periods presented, all potentially dilutive common stock equivalents are antidilutive and have been excluded from the calculation of net loss per share. The diluted net loss per common share was the same for Class A and Class B common shares because they are entitled to the same liquidation and dividend rights.
Segments	Segments Operating segments are defined as components of an entity for which separate financial information is available and that is regularly reviewed by the Chief Operating Decision Maker (“CODM”) in deciding how to allocate resources to an individual segment and in assessing performance. The Company’s CODM is its Chief Executive Officer. The Company has determined that it operates as a single operating segment and one reportable segment, as the CODM reviews financial information presented on a consolidated basis for purposes of making operating decisions, allocating resources, and evaluating financial performance. Given the Company’s pre-revenue operating stage, it currently has no concentration exposure to products, services, or customers.
Comprehensive Loss	Comprehensive Loss Comprehensive loss includes all changes in equity during the period from non-owner sources. The Company’s comprehensive loss consists of its net loss and its unrealized gains or losses on available-for-sale securities.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Recently Adopted Accounting Pronouncements In August 2020, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2020-06, Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity . The ASU simplifies the accounting for convertible instruments by removing certain separation models in ASC 470-20, Debt—Debt with Conversion and Other Options , for convertible instruments. The ASU updates the guidance on certain embedded conversion features that are not required to be accounted for as derivatives under Topic 815, Derivatives and Hedging , or that do not result in substantial premiums accounted for as paid-in capital, such that those features are no longer required to be separated from the host contract. The convertible debt instruments will be accounted for as a single liability measured at amortized cost. Further, the ASU made amendments to the Earnings Per Share (“EPS”) guidance in Topic 260, Earnings Per Share for convertible instruments, the most significant impact of which is requiring the use of the if-converted method for diluted EPS calculation, and no longer allowing the net share settlement method. The ASU also made revisions to Topic 815-40, which provides guidance on how an entity must determine whether a contract qualifies for a scope exception from derivative accounting. The amendments to Topic 815-40 change the scope of contracts that are recognized as assets or liabilities. The Company adopted ASU 2020-06 effective January 1, 2023. The adoption of this guidance did not have a material impact on the Company’s consolidated financial statements. Recently Issued Accounting Pronouncements Not Yet Adopted In November 2023, the FASB issued ASU 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures , which expands reportable segment disclosure requirements through enhanced disclosures about significant segment expenses, interim segment profit or loss and assets, and how the CODM uses reported segment profit or loss information in assessing segment performance and allocating resources. The update is effective for annual periods beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024 on a retrospective basis. Early adoption is permitted. The Company is currently evaluating the impact of ASU 2023-07 on its disclosures within its consolidated financial statements. In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures , which requires disclosure of incremental income tax information related to the income tax rate reconciliation and expanded disclosures of income taxes paid, among other disclosure requirements. ASU 2023-09 is effective for annual periods beginning after December 15, 2024 on a prospective basis, and retrospective application is permitted. The Company is currently evaluating the impact of ASU 2023-09 on its disclosures within its consolidated financial statements.
Cash and Cash Equivalents	Restricted cash consists primarily of cash held as security for the Company’s standby letters of credit.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
Summary of Significant Accounting Policies (Tables)	Dec. 31, 2023
Accounting Policies [Abstract]
Schedule of Cash and Cash Equivalents	The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported in the consolidated balance sheets that sum to amounts reported on the consolidated statements of cash flows (in millions): As of December 31, 2023 2022 Cash and cash equivalents $ 464.6 $ 69.4 Restricted cash 6.9 2.9 Total cash, cash equivalents, and restricted cash $ 471.5 $ 72.3
Schedule of Assets and Liabilities Measured at Fair Value	The following tables present information about the Company’s assets and liabilities that are measured at fair value on a recurring basis as of December 31, 2023 and 2022 and indicate the fair value hierarchy of the valuation inputs the Company utilized to determine such fair value (in millions): As of December 31, 2023 Description Level 1 Level 2 Level 3 Total Assets: Cash equivalents: Money market funds $ 339.6 $ — $ — $ 339.6 Liabilities: Warrant liability – public warrants $ 25.4 $ — $ — $ 25.4 Warrant liability – private placement warrants $ — $ — $ 14.5 $ 14.5 Accrued technology and dispute resolutions agreements liability $ — $ — $ 44.0 $ 44.0 As of December 31, 2022 Description Level 1 Level 2 Level 3 Total Assets: Cash equivalents: Money market funds $ 6.1 $ — $ — $ 6.1 Short-term investments: U.S. Treasury securities $ 316.6 $ — $ — $ 316.6 Corporate debt securities $ — $ 20.1 $ — $ 20.1 Commercial paper $ — $ 125.1 $ — $ 125.1 Liabilities: Warrant liability – public warrants $ 4.5 $ — $ — $ 4.5 Warrant liability – private placement warrants $ — $ — $ 2.5 $ 2.5
Schedule of Cash, Cash Equivalents and Short-term Investments	The following tables present a summary of the Company’s cash equivalents and short-term investments as of December 31, 2023 and 2022 (in millions): As of December 31, 2023 Description Amortized Cost Unrealized Gains Unrealized Losses Fair Value Cash equivalents: Money market funds $ 339.6 $ — $ — $ 339.6 Total $ 339.6 $ — $ — $ 339.6 As of December 31, 2022 Description Amortized Cost Unrealized Gains Unrealized Losses Fair Value Cash equivalents: Money market funds $ 6.1 $ — $ — $ 6.1 Short-term investments: U.S. Treasury securities 317.4 — (0.8) 316.6 Corporate debt securities 20.1 — — 20.1 Commercial paper 125.1 — — 125.1 Total $ 468.7 $ — $ (0.8) $ 467.9
Schedule of Key Inputs into the Monte Carlo Simulation Model for the Private Placement Warrants	The key inputs into the Monte Carlo simulation model for the private placement warrants are as follows: Input December 31, December 31, Stock price $ 6.14 $ 1.87 Strike price $ 11.50 $ 11.50 Dividend yield 0.00 % 0.00 % Term (in years) 2.71 3.71 Volatility 70.15 % 75.00 % Risk-free rate 4.03 % 4.14 % The key inputs into the Monte Carlo simulation model for the accrued technology and dispute resolution agreements liability are as follows: Input December 31, Stock price $ 6.14 Strike price $ 0.01 Dividend yield 0.00 % Term (in years) 0.11 Volatility 60.00 % Risk-free rate 5.40 %
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation	The following table presents the change in fair value of the Company’s Level 3 private placement warrants and accrued technology and dispute resolution agreements liability during the years ended December 31, 2023 and 2022 (in millions): Balance as of December 31, 2021 $ 10.1 Change in fair value (7.6) Balance as of December 31, 2022 2.5 Additions: accrued technology and dispute resolution agreements liability 48.0 Change in fair value 8.0 Balance as of December 31, 2023 (1) $ 58.5 (1) As of December 31, 2023, $14.5 million and $44.0 million were recorded within warrant liabilities and accrued expenses and other current liabilities, respectively, in the consolidated balance sheets.
Schedule of Useful Life for Property, Plant and Equipment	Depreciation on property and equipment is calculated using the straight-line method over the estimated useful lives of the assets as follows: Useful Life (In years) Furniture, fixtures, and equipment 5 Vehicles 5 Computer hardware 3 Computer software 3 Website design 2 Leasehold improvements Shorter of lease term or the asset standard life Property and equipment, net, consisted of the following (in millions): As of December 31, 2023 2022 Furniture, fixtures, and equipment $ 7.9 $ 1.5 Vehicles 0.1 — Computer hardware 5.3 4.5 Computer software 1.5 0.7 Website design 0.8 0.7 Leasehold improvements 33.0 2.9 Construction in progress 18.4 4.8 Total property and equipment 67.0 15.1 Less: Accumulated depreciation (9.4) (3.6) Total property and equipment, net $ 57.6 $ 11.5 The following table presents depreciation expense included in each respective expense category in the consolidated statements of operations (in millions): Year Ended December 31, 2023 2022 2021 Research and development $ 5.3 $ 2.3 $ 0.9 General and administrative 0.5 0.8 0.4 Total depreciation expense $ 5.8 $ 3.1 $ 1.3
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	The following table presents the number of antidilutive shares excluded from the calculation of diluted net loss per share: Year Ended December 31, 2023 2022 2021 Options to purchase common stock 3,174,114 5,335,974 9,444,221 Unvested restricted stock units 33,397,483 45,021,632 38,124,396 Warrants 52,011,560 30,558,565 32,519,357 Shares issuable under the employee stock purchase plan (Note 10) 931,412 712,838 — Total 89,514,569 81,629,009 80,087,974

Reverse Recapitalization and _2

Reverse Recapitalization and Related Transactions (Tables)	12 Months Ended
Reverse Recapitalization and Related Transactions (Tables)	Dec. 31, 2023
Reverse Recapitalization [Abstract]
Schedule of Reverse Recapitalization	The net assets of Atlas were recognized at their carrying value immediately prior to the closing of the Business Combination with no goodwill or other intangible assets recorded and were as follows, net of transaction costs (in millions): Cash $ 201.8 Warrant liability (39.5) Net assets acquired $ 162.3 The number of shares of common stock issued immediately following the consummation of the Business Combination were as follows: Number of shares Class A and B common stock outstanding on July 1, 2021 52,572,374 Common stock issued through option exercises between July 1, 2021 and September 16, 2021 4,738,344 Vesting of unvested shares between July 1, 2021 and September 16, 2021 2,540,925 Common stock outstanding prior to the Business Combination 59,851,643 Conversion of preferred stock 64,884,120 Common stock attributable to Atlas 36,385,693 Adjustment related to reverse recapitalization* 101,269,813 Restricted stock units vested at closing 10,004,612 Common stock attributable to PIPE Financing 61,512,500 Total shares of common stock as of closing of the Business Combination and related transactions as of September 16, 2021 232,638,568 * The corresponding adjustment to additional paid-in-capital related to the reverse recapitalization was comprised of (i) $162.3 million which represents the fair value of the consideration transferred in the Business Combination, less the excess of the fair value of the shares issued over the value of the net monetary assets of Atlas, net of transaction costs and (ii) $61.5 million which represents the conversion of the convertible preferred stock into New Archer Class A and Class B common stock.

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	12 Months Ended
Property and Equipment, Net (Tables)	Dec. 31, 2023
Property, Plant and Equipment [Abstract]
Schedule of Property, Plant and Equipment Net	Depreciation on property and equipment is calculated using the straight-line method over the estimated useful lives of the assets as follows: Useful Life (In years) Furniture, fixtures, and equipment 5 Vehicles 5 Computer hardware 3 Computer software 3 Website design 2 Leasehold improvements Shorter of lease term or the asset standard life Property and equipment, net, consisted of the following (in millions): As of December 31, 2023 2022 Furniture, fixtures, and equipment $ 7.9 $ 1.5 Vehicles 0.1 — Computer hardware 5.3 4.5 Computer software 1.5 0.7 Website design 0.8 0.7 Leasehold improvements 33.0 2.9 Construction in progress 18.4 4.8 Total property and equipment 67.0 15.1 Less: Accumulated depreciation (9.4) (3.6) Total property and equipment, net $ 57.6 $ 11.5 The following table presents depreciation expense included in each respective expense category in the consolidated statements of operations (in millions): Year Ended December 31, 2023 2022 2021 Research and development $ 5.3 $ 2.3 $ 0.9 General and administrative 0.5 0.8 0.4 Total depreciation expense $ 5.8 $ 3.1 $ 1.3

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities (Tables)	12 Months Ended
Accrued Expenses and Other Current Liabilities (Tables)	Dec. 31, 2023
Other Liabilities Disclosure [Abstract]
Other Current Liabilities	Accrued expenses and other current liabilities consisted of the following (in millions): As of December 31, 2023 2022 Accrued professional fees $ 9.5 $ 17.2 Accrued employee costs 16.7 7.8 Accrued parts and materials 12.1 5.2 Taxes payable 1.4 0.3 Accrued capital expenditures 9.2 2.9 Accrued cloud computing implementation costs 0.3 2.0 Accrued marketing fees — 0.2 Accrued technology and dispute resolution agreements liability (Note 8 ) 44.0 — Other current liabilities 3.7 1.1 Total $ 96.9 $ 36.7

Notes Payable (Tables)

Notes Payable (Tables)	12 Months Ended
Notes Payable (Tables)	Dec. 31, 2023
Debt Disclosure [Abstract]
Schedule of Long-term Debt Instruments	The Company’s notes payable consisted of the following (in millions): As of December 31, 2023 2022 Synovus Bank Loan $ 7.5 $ — Loan unamortized discount and loan issuance costs (0.3) — Silicon Valley Bank (“SVB”) Term Loans — 10.0 Term Loans unamortized discount and loan issuance costs — (0.7) Total debt, net of discount and loan issuance costs 7.2 9.3 Less current portion, net of discount and loan issuance costs — (9.3) Total long-term notes payable, net of discount and loan issuance costs $ 7.2 $ —
Schedule of Maturities of Long-term Debt	The future scheduled principal maturities of the Loan as of December 31, 2023 are as follows (in millions): 2024 $ — 2025 — 2026 0.1 2027 0.3 2028 0.3 2029 and thereafter 6.8 $ 7.5

Commitment and Contingencies (T

Commitment and Contingencies (Tables)	12 Months Ended
Commitment and Contingencies (Tables)	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Summary of Lease Costs	The Company’s lease costs were as follows (in millions): Year Ended December 31, 2023 2022 2021 Operating lease cost $ 5.7 $ 5.8 $ 2.1 Short-term lease cost 0.6 0.2 — Total lease cost $ 6.3 $ 6.0 $ 2.1 The Company’s weighted-average remaining lease term and discount rate as of December 31, 2023 and 2022 were as follows: 2023 2022 Weighted-average remaining lease term (in months) 58 46 Weighted-average discount rate 14.74 % 13.78 % Supplemental cash flow information and non-cash activities related to right-of-use assets and lease liabilities were as follows (in millions): Year Ended December 31, 2023 2022 2021 Operating cash outflows from operating leases $ 5.0 $ 4.3 $ 1.9 Operating lease liabilities from obtaining right-of-use assets 0.6 11.7 3.6
Summary of Operating Lease Maturities	The minimum aggregate future obligations under the Company’s non-cancelable operating leases as of December 31, 2023 were as follows (in millions): 2024 $ 5.5 2025 5.1 2026 4.6 2027 2.2 2028 2.2 Thereafter 4.4 Total future lease payments 24.0 Less: leasehold improvement allowance (0.7) Total net future lease payments 23.3 Less: imputed interest (7.3) Present value of future lease payments $ 16.0

Stock-Based Compensation_ (Tabl

Stock-Based Compensation (Tables)	12 Months Ended
Stock-Based Compensation (Tables)	Dec. 31, 2023
Share-Based Payment Arrangement [Abstract]
Schedule of Share-Based Payment Award, Employee Stock Purchase Plan, Valuation Assumptions	The following table sets forth the key assumptions and fair value results for each award granted in the Company’s six-month offering period that started on December 1, 2023: Input December 1, 2023 Stock price $ 6.30 Risk-free interest rate 5.26 % Term (in years) 0.50 Volatility 97.50 % Dividend yield 0.00 % Grant date fair value per share $ 2.62
Share-based Payment Arrangement, Option, Activity	A summary of the Company’s stock option activity is as follows: Number of Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Life (Years) Aggregate Intrinsic Value (In millions) Outstanding as of January 1, 2023 5,335,974 $ 0.12 7.66 $ 9.4 Exercised (2,027,221) 0.12 7.8 Expired/forfeited (134,639) 0.12 Outstanding as of December 31, 2023 3,174,114 0.12 6.66 19.1 Exercisable as of December 31, 2023 1,346,269 $ 0.13 6.75 $ 8.1 Vested and expected to vest as of December 31, 2023 3,174,114 0.12 6.66 19.1
Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions	The assumptions used in the Black-Scholes option pricing model to estimate the fair value of the stock options granted during the year ended December 31, 2021 are provided in the following table: December 31, 2021 Risk-free interest rate: Employee stock options 0.62 % Non-employee stock options 1.08 % Expected term (in years): Employee stock options 6.32 Non-employee stock options 10.00 Expected volatility: Employee stock options 87.94 % Non-employee stock options 88.03 % Dividend yield: Employee stock options 0.00 % Non-employee stock options 0.00 % Grant date fair value per share: Employee stock options $ 13.65 Non-employee stock options $ 13.68
Share-based Payment Arrangement, Restricted Stock Unit, Activity	A summary of the Company’s RSU activity is as follows: Number of Shares Weighted Average Grant Price Outstanding as of January 1, 2023 43,146,632 $ 5.72 Granted 11,864,674 3.36 Vested (7,555,232) 3.95 Forfeited (15,933,591) 6.26 Outstanding as of December 31, 2023 31,522,483 4.99
Schedule of Share-Based Payment Award, Equity Instruments Other Than Options, Valuation Assumptions	The following assumptions were used to estimate the fair value, using the Monte Carlo simulation, of the market award grant: September 16, 2021 Stock price $ 9.92 Term (in years) 7 Volatility 55.00 % Risk-free interest rate 1.13 % Dividend yield 0.00 %
Share-based Payment Arrangement, Expensed and Capitalized, Amount	The following table presents stock-based compensation expense included in each respective expense category in the consolidated statements of operations (in millions): Year Ended December 31, 2023 2022 2021 Research and development $ 28.9 $ 26.1 $ 3.7 General and administrative 16.3 76.7 119.9 Total stock-based compensation expense $ 45.2 $ 102.8 $ 123.6
Share-based Payment Arrangement, Warrant Activity	A summary of the Company’s warrant activity is as follows: Number of Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Life (Years) Aggregate Intrinsic Value (In millions) Outstanding as of January 1, 2023 8,736,599 $ 0.01 7.84 $ 16.3 Issued 15,000,000 0.01 Exercised (2,948,352) 0.01 17.0 Outstanding as of December 31, 2023 20,788,247 0.01 4.48 127.4 Vested as of December 31, 2023 2,839,893 $ 0.01 2.17 $ 17.4

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
Income Taxes (Tables)	Dec. 31, 2023
Income Tax Disclosure [Abstract]
Schedule of Income before Income Tax, Domestic and Foreign	The Company's loss before income taxes consisted of the following (in millions): Year Ended December 31, 2023 2022 2021 United States $ (458.7) $ (317.3) $ (347.8) International 1.3 — — Total $ (457.4) $ (317.3) $ (347.8)
Schedule of Effective Income Tax Rate Reconciliation	A reconciliation of the Company’s effective income tax rate to the expected income tax rate, computed by applying the federal statutory income tax rate of 21% to the Company’s loss before income taxes, is as follows: Year Ended December 31, 2023 2022 2021 Federal income tax (benefit) at statutory tax rate 21.0 % 21.0 % 21.0 % State and local income taxes (net of federal benefit) (2.7) % 2.5 % 2.6 % Nondeductible expenses (0.1) % (0.2) % (0.2) % Warrant expense (1.6) % 0.8 % (6.5) % Nondeductible officers’ compensation 0.1 % (4.7) % (6.9) % Other 0.0 % (0.7) % 0.2 % Credits 4.4 % 4.9 % 1.3 % Change in valuation allowance (21.2) % (23.6) % (11.5) % Effective tax rate (0.1) % 0.0 % 0.0 %
Schedule of Deferred Tax Assets and Liabilities	The tax effects of temporary differences that give rise to significant portions of the deferred tax assets and deferred tax liabilities are provided below (in millions): As of December 31, 2023 2022 Deferred tax assets: Net operating loss carryforwards $ 84.1 $ 43.4 Accrued expenses 12.4 1.5 Operating lease liabilities 3.5 3.3 Stock-based compensation 1.9 3.7 Warrants 6.0 2.5 Capitalized R&D expenses 77.8 51.7 Credits 41.7 21.1 Start-up costs 3.8 4.7 Other 0.7 0.9 Gross deferred tax assets 231.9 132.8 Less: valuation allowance (226.3) (129.7) Deferred tax assets, net of valuation allowance 5.6 3.1 Deferred tax liabilities: Depreciation and amortization (3.7) — Right-of-use assets (1.9) (3.1) Total deferred tax liabilities (5.6) (3.1) Total net deferred tax assets $ — $ —
Schedule of Unrecognized Tax Benefits Roll Forward	The following table summarizes the activity related to the Company’s unrecognized tax benefits during the years ended December 31, 2023, 2022 and 2021 (in millions): Balance as of December 31, 2020 $ 2.0 Increases related to current year tax positions 0.3 Decreases based on tax positions related to prior years (2.0) Balance as of December 31, 2021 0.3 Increases related to current year tax positions 1.2 Balance as of December 31, 2022 1.5 Increases related to current year tax positions 0.5 Balance as of December 31, 2023 $ 2.0

Organization and Nature of Bu_2

Organization and Nature of Business (Details)	12 Months Ended
Organization and Nature of Business (Details)	Dec. 31, 2023 lineOfBusiness
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of lines of business	2

Liquidity and Going Concern (De

Liquidity and Going Concern (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accumulated deficit	$ 1,148.8	$ 690.9
Reverse recapitalization net proceeds received	801.8
Cash and cash equivalents	$ 464.6	$ 69.4

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Narrative (Details)	12 Months Ended
	Dec. 31, 2023 USD ($) $ / shares segment	Dec. 31, 2022 USD ($) $ / shares	Dec. 31, 2021 USD ($)
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	$ 464,600,000	$ 69,400,000
Change in fair value of warrant liabilities and other warrant costs	$ 32,900,000	23,300,000	$ 10,400,000
Finite-lived intangible asset, useful life	15 years
Impairment of intangible assets	$ 0	0	0
Intangible assets, net	400,000	400,000
Capitalized cloud computing implementation costs	6,400,000	3,700,000
Contract liabilities	$ 10,800,000	10,000,000
Number of operating segments \| segment	1
Number of reportable segments \| segment	1
United States Air Force
Cash and Cash Equivalents [Line Items]
Purchase agreement, installment payment received	$ 800,000
United Airlines Inc.
Cash and Cash Equivalents [Line Items]
Contract with customer liabilities, pre-delivery payment	10,000,000	10,000,000
Contract with liability, revenue recognized	0	$ 0	$ 0
Accrued Technology and Dispute Resolution Agreement \| General and administrative
Cash and Cash Equivalents [Line Items]
Agreements liability, fair value adjustment	$ 4,000,000
Stock price
Cash and Cash Equivalents [Line Items]
Warrant liability, measurement input \| $ / shares	6.14	1.87
Public Warrants \| Stock price
Cash and Cash Equivalents [Line Items]
Warrant liability, measurement input \| $ / shares	1.46	0.26
Money market funds
Cash and Cash Equivalents [Line Items]
Cash equivalents:	$ 339,600,000	$ 6,100,000
Cash and cash equivalents		6,100,000
Money market funds \| Recurring
Cash and Cash Equivalents [Line Items]
Cash equivalents:	339,600,000	6,100,000
Money market funds \| Level 1 \| Recurring
Cash and Cash Equivalents [Line Items]
Cash equivalents:	$ 339,600,000	$ 6,100,000

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Schedule of Cash, Cash Equivalents, and Restricted Cash (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Accounting Policies [Abstract]
Cash and cash equivalents	$ 464.6	$ 69.4
Restricted cash	6.9	2.9
Total cash, cash equivalents, and restricted cash	$ 471.5	$ 72.3	$ 746.9	$ 36.6

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Fair Value Recurring Basis (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments:	$ 0	$ 461.8
Accrued technology and dispute resolutions agreements liability	44	0
Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents, fair value	339.6	6.1
Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Accrued technology and dispute resolutions agreements liability	44
Recurring \| Public Warrants
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrant liability, fair value	25.4	4.5
Recurring \| Private Placement Warrants
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrant liability, fair value	14.5	2.5
Recurring \| U.S. Treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments:		316.6
Recurring \| Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments:		20.1
Recurring \| Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments:		125.1
Recurring \| Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents, fair value	339.6	6.1
Recurring \| Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Accrued technology and dispute resolutions agreements liability	0
Recurring \| Level 1 \| Public Warrants
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrant liability, fair value	25.4	4.5
Recurring \| Level 1 \| Private Placement Warrants
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrant liability, fair value	0	0
Recurring \| Level 1 \| U.S. Treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments:		316.6
Recurring \| Level 1 \| Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments:		0
Recurring \| Level 1 \| Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments:		0
Recurring \| Level 1 \| Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents, fair value	339.6	6.1
Recurring \| Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Accrued technology and dispute resolutions agreements liability	0
Recurring \| Level 2 \| Public Warrants
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrant liability, fair value	0	0
Recurring \| Level 2 \| Private Placement Warrants
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrant liability, fair value	0	0
Recurring \| Level 2 \| U.S. Treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments:		0
Recurring \| Level 2 \| Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments:		20.1
Recurring \| Level 2 \| Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments:		125.1
Recurring \| Level 2 \| Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents, fair value	0	0
Recurring \| Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Accrued technology and dispute resolutions agreements liability	44
Recurring \| Level 3 \| Public Warrants
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrant liability, fair value	0	0
Recurring \| Level 3 \| Private Placement Warrants
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrant liability, fair value	14.5	2.5
Recurring \| Level 3 \| U.S. Treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments:		0
Recurring \| Level 3 \| Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments:		0
Recurring \| Level 3 \| Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments:		0
Recurring \| Level 3 \| Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents, fair value	$ 0	$ 0

Summary of Significant Accoun_7

Summary of Significant Accounting Policies - Cash, Cash Equivalents, and Short-Term Investments (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Short-term investments:
Unrealized Gains	$ 0	$ 0
Unrealized Losses	0	(0.8)
Amortized Cost	339.6	468.7
Fair Value	339.6	467.9
U.S. Treasury securities
Short-term investments:
Amortized Cost		317.4
Unrealized Gains		0
Unrealized Losses		(0.8)
Fair Value		316.6
Corporate debt securities
Short-term investments:
Amortized Cost		20.1
Unrealized Gains		0
Unrealized Losses		0
Fair Value		20.1
Commercial paper
Short-term investments:
Amortized Cost		125.1
Unrealized Gains		0
Unrealized Losses		0
Fair Value		125.1
Money market funds
Cash equivalents:
Cash equivalents:	$ 339.6	$ 6.1

Summary of Significant Accoun_8

Summary of Significant Accounting Policies - Schedule of Key Inputs into the Monte Carlo Simulation Model for the Private Placement Warrants (Details)	12 Months Ended
	Dec. 31, 2023 $ / shares	Dec. 31, 2022 $ / shares
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants outstanding, term	2 years 8 months 15 days	3 years 8 months 15 days
Accrued technology and dispute resolution agreements liability, term	1 month 9 days
Stock price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrant liability, measurement input (in dollars per share)	6.14	1.87
Accrued technology and dispute resolution agreements liability, measurement input	6.14
Strike price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrant liability, measurement input (in dollars per share)	11.50	11.50
Accrued technology and dispute resolution agreements liability, measurement input	0.01
Dividend yield
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrant liability, measurement input (in dollars per share)	0	0
Accrued technology and dispute resolution agreements liability, measurement input	0
Volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrant liability, measurement input (in dollars per share)	0.7015	0.7500
Accrued technology and dispute resolution agreements liability, measurement input	0.6000
Risk-free rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrant liability, measurement input (in dollars per share)	0.0403	0.0414
Accrued technology and dispute resolution agreements liability, measurement input	0.0540

Summary of Significant Accoun_9

Summary of Significant Accounting Policies - Measurement Input (Details)	12 Months Ended
	Dec. 31, 2023 $ / shares	Dec. 31, 2022 $ / shares
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants outstanding, term	2 years 8 months 15 days	3 years 8 months 15 days
Stock price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrant liability, measurement input	6.14	1.87
Strike price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrant liability, measurement input	11.50	11.50
Dividend yield
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrant liability, measurement input	0	0
Volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrant liability, measurement input	0.7015	0.7500
Risk-free rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrant liability, measurement input	0.0403	0.0414

Summary of Significant Accou_10

Summary of Significant Accounting Policies - Private Placement Warrants (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Warrant liabilities	$ 39.9	$ 7
Accrued expenses and other current liabilities	96.9	36.7
Warrant Subject to Vesting Criteria
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Accrued expenses and other current liabilities	44
Private Placement Warrants and Accrued Technology and Dispute Resolution Agreement
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Warrant liabilities	14.5
Private Placement Warrants and Accrued Technology and Dispute Resolution Agreement \| Level 3
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	2.5	10.1
Change in fair value	8	(7.6)
Additions: accrued technology and dispute resolution agreements liability	48
Ending balance	$ 58.5	$ 2.5

Summary of Significant Accou_11

Summary of Significant Accounting Policies - Property Plant and Equipment (Details)	Dec. 31, 2023
Furniture, fixtures, and equipment
Property, Plant and Equipment [Line Items]
Useful Life (In years)	5 years
Vehicles
Property, Plant and Equipment [Line Items]
Useful Life (In years)	5 years
Computer hardware
Property, Plant and Equipment [Line Items]
Useful Life (In years)	3 years
Computer software
Property, Plant and Equipment [Line Items]
Useful Life (In years)	3 years
Website design
Property, Plant and Equipment [Line Items]
Useful Life (In years)	2 years

Summary of Significant Accou_12

Summary of Significant Accounting Policies - Schedule of Antidilutive Securities (Details) - shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation (in shares)	89,514,569	81,629,009	80,087,974
Options to purchase common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation (in shares)	3,174,114	5,335,974	9,444,221
Unvested restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation (in shares)	33,397,483	45,021,632	38,124,396
Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation (in shares)	52,011,560	30,558,565	32,519,357
Shares issuable under the Employee Stock Purchase Plan
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation (in shares)	931,412	712,838	0

Reverse Recapitalization and _3

Reverse Recapitalization and Related Transactions - Narrative (Details) $ / shares in Units, $ in Millions			12 Months Ended
	Sep. 16, 2021 USD ($) trading_day $ / shares shares	Sep. 15, 2021 shares	Dec. 31, 2023 USD ($) $ / shares shares	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Jan. 01, 2023 shares	Apr. 30, 2022 shares	Jan. 29, 2021 $ / shares
Schedule Of Reverse Recapitalization [Line Items]
Recapitalization exchange ratio	1.00656519
Recapitalization transaction \| $	$ 257.6		$ 0	$ 0	$ 257.6
Proceeds from reverse recapitalization, net of redemptions \| $	$ 242.4
Conversion of stock (in shares)	1		1
Contingent consideration, equity, earnout period	3 years
Contingent consideration, equity, stock price trigger (in dollars per share) \| $ / shares	$ 12
Contingent consideration, equity, threshold trading days \| trading_day	10
Contingent consideration, equity, threshold consecutive trading days \| trading_day	20
Conversion of stock (in shares)	64,884,120
Capital shares reserved for future issuance (in shares)	60,260,483
Number of shares issued in transaction (in shares)	60,000,000
Price per share (in dollars per share) \| $ / shares	$ 10
Consideration received on transaction \| $	$ 600
Shares issued for business combination and PIPE financing fees (in shares)	1,512,500
Warrant outstanding (in shares)	24,666,667
Warrants price per share (in dollars per share) \| $ / shares	$ 11.50							$ 0.01
Direct and incremental transaction, aggregate cost \| $	$ 81.8
Reverse recapitalization, transaction costs \| $	10.9
Adjustments to additional paid in capital, stock issued, issuance costs \| $	$ 55.8
Public Warrants
Schedule Of Reverse Recapitalization [Line Items]
Warrant outstanding (in shares)	16,666,667		17,398,947
Warrants price per share (in dollars per share) \| $ / shares			$ 0.01
Private Warrants
Schedule Of Reverse Recapitalization [Line Items]
Warrant outstanding (in shares)	8,000,000
Unvested restricted stock units
Schedule Of Reverse Recapitalization [Line Items]
Vested (in shares)			7,555,232
2019 Equity Incentive Plan
Schedule Of Reverse Recapitalization [Line Items]
Options and restricted stock units, outstanding, number (in shares)	56,390,023
Warrant outstanding (in shares)	13,112,602
Options, restricted stock units and warrants issued (in shares)	70,265,095
2019 Equity Incentive Plan \| Unvested restricted stock units
Schedule Of Reverse Recapitalization [Line Items]
Vested (in shares)	10,004,612
Atlas
Schedule Of Reverse Recapitalization [Line Items]
Contingent consideration, equity, shares (in shares)	1,875,000
Class A
Schedule Of Reverse Recapitalization [Line Items]
Stock-based compensation \| $	$ 15.1
Class A \| Public Warrants
Schedule Of Reverse Recapitalization [Line Items]
Warrants price per share (in dollars per share) \| $ / shares			$ 11.50
Class A \| 2021 Stock Plan
Schedule Of Reverse Recapitalization [Line Items]
Capital shares reserved for future issuance (in shares)						12,292,155	34,175,708
Class B
Schedule Of Reverse Recapitalization [Line Items]
Vested (in shares)	10,004,612
Class B \| Unvested restricted stock units
Schedule Of Reverse Recapitalization [Line Items]
Vested (in shares)		5,002,306
Series Seed and Series A Redeemable Convertible Preferred Stock
Schedule Of Reverse Recapitalization [Line Items]
Conversion of stock (in shares)	64,884,120
Common Stock
Schedule Of Reverse Recapitalization [Line Items]
Shares issued following conversion (in shares)	124,735,762
Common Stock \| Class A
Schedule Of Reverse Recapitalization [Line Items]
Shares issued following conversion (in shares)	54,987,838
Number of shares issued in transaction (in shares)			3,109,097
Common Stock \| Class B
Schedule Of Reverse Recapitalization [Line Items]
Shares issued following conversion (in shares)	69,747,924

Reverse Recapitalization and _4

Reverse Recapitalization and Related Transactions - Transaction Costs (Details) $ in Millions	Sep. 16, 2021 USD ($)
Reverse Recapitalization [Abstract]
Cash	$ 201.8
Warrant liability	(39.5)
Net assets acquired	$ 162.3

Reverse Recapitalization and _5

Reverse Recapitalization and Related Transactions - Schedule of Common Stock Issued (Details) - USD ($) $ in Millions		2 Months Ended	12 Months Ended
	Sep. 16, 2021	Sep. 15, 2021	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Reverse Recapitalization [Roll Forward]
Common stock, beginning balance (in shares)	59,851,643
Common Stock issued through option exercises between July 1, 2021 and September 16, 2021 (in shares)		4,738,344
Vesting of unvested shares between July 1, 2021 and September 16, 2021 (in shares)		2,540,925
Common stock, ending balance (in shares)	232,638,568	59,851,643
Conversion of stock (in shares)	64,884,120
Adjustment related to Reverse Recapitalization (in shares)	101,269,813
Restricted stock units vested at closing (in shares)	10,004,612
Common stock attributable to PIPE Financing (in shares)	61,512,500
Conversion of convertible preferred stock to common stock in connection with the reverse recapitalization			$ 0	$ 0	$ 61.5
Series Seed and Series A Redeemable Convertible Preferred Stock
Reverse Recapitalization [Roll Forward]
Conversion of stock (in shares)	64,884,120
Conversion of convertible preferred stock to common stock in connection with the reverse recapitalization	$ 61.5
Additional Paid-in Capital
Reverse Recapitalization [Roll Forward]
Stock-based compensation	$ 162.3
Atlas
Reverse Recapitalization [Roll Forward]
Common stock attributable to Atlas (in shares)	36,385,693
Legacy Archer
Reverse Recapitalization [Roll Forward]
Common stock, beginning balance (in shares)		52,572,374

Property and Equipment, Net (De

Property and Equipment, Net (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 67	$ 15.1
Less: Accumulated depreciation	(9.4)	(3.6)
Total property and equipment, net	57.6	11.5
Furniture, fixtures, and equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	7.9	1.5
Vehicles
Property, Plant and Equipment [Line Items]
Total property and equipment	0.1	0
Computer hardware
Property, Plant and Equipment [Line Items]
Total property and equipment	5.3	4.5
Computer software
Property, Plant and Equipment [Line Items]
Total property and equipment	1.5	0.7
Website design
Property, Plant and Equipment [Line Items]
Total property and equipment	0.8	0.7
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total property and equipment	33	2.9
Construction in progress
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 18.4	$ 4.8

Property and Equipment, Net - D

Property and Equipment, Net - Depreciation Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Depreciation
Total depreciation expense	$ 5.8	$ 3.1	$ 1.3
Research and development
Depreciation
Total depreciation expense	5.3	2.3	0.9
General and administrative
Depreciation
Total depreciation expense	$ 0.5	$ 0.8	$ 0.4

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Other Liabilities Disclosure [Abstract]
Accrued professional fees	$ 9.5	$ 17.2
Accrued employee costs	16.7	7.8
Accrued parts and materials	12.1	5.2
Taxes payable	1.4	0.3
Accrued capital expenditures	9.2	2.9
Accrued cloud computing implementation costs	0.3	2
Accrued marketing fees	0	0.2
Accrued technology and dispute resolutions agreements liability	44	0
Other current liabilities	3.7	1.1
Total	$ 96.9	$ 36.7

Notes Payable - Schedule of Lon

Notes Payable - Schedule of Long-term Debt Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
Long-term debt, gross	$ 7,500
Total debt, net of discount and loan issuance costs	7,200	$ 9,300
Less current portion, net of discount and loan issuance costs	0	(9,300)
Total long-term notes payable, net of discount and loan issuance costs	7,200	0
SVB Term Loans \| Secured Debt
Debt Instrument [Line Items]
Long-term debt, gross	0	10,000
Term Loans unamortized discount and loan issuance costs	0	(700)
Credit Facility \| Synovus Bank Loan
Debt Instrument [Line Items]
Long-term debt, gross	7,500	0
Term Loans unamortized discount and loan issuance costs	(300)	$ 0
Total debt, net of discount and loan issuance costs	$ 7,200

Notes Payable - Narrative (Deta

Notes Payable - Narrative (Details)			12 Months Ended
Notes Payable - Narrative (Details)	Oct. 05, 2023 USD ($)	Jul. 09, 2021 USD ($) shares	Dec. 31, 2023 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) $ / shares	Dec. 31, 2021 USD ($)	Nov. 14, 2026 installment	Nov. 14, 2023 interest	Jan. 01, 2022 installment
Debt Instrument [Line Items]
Proceeds from issuance of common stock			$ 300,000	$ 0	$ 200,000
Long-term debt			7,200,000	9,300,000
Debt discount and issuance cost amortization			$ 700,000	$ 500,000	200,000
Stock price
Debt Instrument [Line Items]
Warrant liability, measurement input \| $ / shares			6.14	1.87
Warrants for Consideration of Term Loan
Debt Instrument [Line Items]
Warrants, issued or issuable (in shares) \| shares		732,280
Number of securities called by each warrant or right (in shares) \| shares		1
Public Warrants
Debt Instrument [Line Items]
Number of securities called by each warrant or right (in shares) \| shares			1
Public Warrants \| Stock price
Debt Instrument [Line Items]
Warrant liability, measurement input \| $ / shares			1.46	0.26
Silicon Valley Bank (“SVB”) \| Warrants for Consideration of Term Loan
Debt Instrument [Line Items]
Warrants, issued or issuable (in shares) \| shares		366,140
SVB Innovation Credit Fund VIII, L.P. (“SVB Innovation”) \| Warrants for Consideration of Term Loan
Debt Instrument [Line Items]
Warrants, issued or issuable (in shares) \| shares		366,140
Credit Facility \| Synovus Bank Loan
Debt Instrument [Line Items]
Proceeds from lines of credit			$ 7,500,000
Proceeds from issuance of common stock			300,000
Interest expense, debt			100,000
Issuance costs			300,000
Long-term debt			$ 7,200,000
Credit Facility \| Synovus Bank Loan \| Minimum
Debt Instrument [Line Items]
Effective rate			7.66%
Credit Facility \| Synovus Bank Loan \| Maximum
Debt Instrument [Line Items]
Effective rate			8.17%
Secured Debt
Debt Instrument [Line Items]
Line of credit, borrowing capacity	$ 65,000,000
Secured Debt \| Synovus Bank Loan
Debt Instrument [Line Items]
Number of monthly interest payment \| interest							120
Increase in annual interest rate upon event of default	5%
Secured Debt \| Synovus Bank Loan \| Forecast
Debt Instrument [Line Items]
Number of monthly installments \| installment						84
Secured Debt \| SVB Term Loans
Debt Instrument [Line Items]
Interest expense, debt			$ 600,000	$ 1,500,000	$ 900,000
Debt instrument, face amount		$ 20,000,000
Number of monthly installments \| installment								24
Interest rate			8.50%
Effective rate			10.20%	9.40%	9.02%
Increase in annual interest rate upon event of default			2%
Debt discount and issuance cost amortization			$ 700,000	$ 500,000	$ 200,000
Secured Debt \| Secured Overnight Financing Rate (SOFR)
Debt Instrument [Line Items]
Basis spread on variable rate	2%

Notes Payable - Maturity Schedu

Notes Payable - Maturity Schedule (Details) $ in Thousands	Dec. 31, 2023 USD ($)
Debt Disclosure [Abstract]
2024	$ 0
2025	0
2026	100
2027	300
2028	300
2029 and thereafter	6,800
Long-term debt	$ 7,500

Commitment and Contingencies -

Commitment and Contingencies - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Aug. 10, 2023	Feb. 28, 2023	Dec. 31, 2022	Sep. 16, 2021	Jan. 29, 2021
Debt Instrument [Line Items]
Warrant outstanding (in shares)					24,666,667
Warrants price per share (in dollars per share)					$ 11.50	$ 0.01
General and administrative expense, noncash charges	$ 70,300,000
Private Placement
Debt Instrument [Line Items]
Warrant outstanding (in shares)		13,176,895
Warrants price per share (in dollars per share)		$ 0.01
Class A
Debt Instrument [Line Items]
Common stock, par value (in dollars per share)	$ 0.0001			$ 0.0001
First Boeing Investment \| Class A \| Private Placement
Debt Instrument [Line Items]
Common stock, par value (in dollars per share)		$ 0.0001
Initial Vested Share Tranche \| Private Placement
Debt Instrument [Line Items]
Sale of stock, shares exercisable (in shares)		4,512,636
General and administrative expense, noncash charges	$ 26,300,000
Second Tranche \| Private Placement
Debt Instrument [Line Items]
Sale of stock, shares exercisable (in shares)		8,664,259
Warrant Subject to Vesting Criteria \| Private Placement
Debt Instrument [Line Items]
General and administrative expense, noncash charges	44,000,000
Standby Letters of Credit \| Line of Credit
Debt Instrument [Line Items]
Line of credit, borrowing capacity			$ 3,500,000
Line of credit	$ 5,900,000

Commitment and Contingencies _2

Commitment and Contingencies - Lease Costs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Operating lease cost	$ 5.7	$ 5.8	$ 2.1
Short-term lease cost	0.6	0.2	0
Total lease cost	$ 6.3	$ 6	$ 2.1
Weighted-average remaining lease term (in months)	58 months	46 months
Weighted-average discount rate	14.74%	13.78%

Commitment and Contingencies _3

Commitment and Contingencies - Operating Lease Schedule of Maturity (Details) $ in Thousands	Dec. 31, 2023 USD ($)
Commitments and Contingencies Disclosure [Abstract]
2024	$ 5,500
2025	5,100
2026	4,600
2027	2,200
2028	2,200
Thereafter	4,400
Total future lease payments	24,000
Less: leasehold improvement allowance	(700)
Total net future lease payments	23,300
Less: imputed interest	(7,300)
Present value of future lease payments	$ 16,000

Commitment and Contingencies _4

Commitment and Contingencies - Noncash Lease Activities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Operating cash outflows from operating leases	$ 5	$ 4.3	$ 1.9
Operating lease liabilities from obtaining right-of-use assets	$ 0.6	$ 11.7	$ 3.6

Preferred and Common Stock (Det

Preferred and Common Stock (Details)			1 Months Ended	12 Months Ended
Preferred and Common Stock (Details)	Aug. 10, 2023 USD ($) shares	Sep. 16, 2021 USD ($) shares	Nov. 30, 2023 USD ($)	Dec. 31, 2023 USD ($) vote shares	Dec. 31, 2022 shares	Dec. 31, 2021 shares
Class of Stock [Line Items]
Preferred stock, outstanding (in shares)				0	0
Conversion of stock (in shares)		1		1
Period following that a founder ceases services to the company				12 months
Number of shares issued in transaction (in shares)		60,000,000
Consideration received on transaction \| $		$ 600,000,000
Private Placement
Class of Stock [Line Items]
Number of shares issued in transaction (in shares)	26,173,286
Consideration received on transaction \| $	$ 139,000,000
At-The-Market Offerings
Class of Stock [Line Items]
Consideration received on transaction \| $			$ 70,000,000
Remaining amount \| $				$ 49,300,000
At-The-Market Offerings \| Maximum
Class of Stock [Line Items]
Commission fee, percentage			3%
Class A
Class of Stock [Line Items]
Voting rights, votes per share \| vote				1
Class A \| Common Stock
Class of Stock [Line Items]
Conversion of stock (in shares)				26,449,869	8,406,170	5,337,446
Number of shares issued in transaction (in shares)				3,109,097
Class A \| Common Stock \| At-The-Market Offerings
Class of Stock [Line Items]
Number of shares issued in transaction (in shares)				3,109,097
Proceeds from sale of stock \| $				$ 19,500,000
Class B
Class of Stock [Line Items]
Voting rights, votes per share \| vote				10
Conversion period				10 years
Percentage of Class B represents the aggregate of Class A				0.10
Percentage of founder shares held				0.80
Common stock, conversion terms, percent of shareholders needed				66.67%
Class B \| Common Stock
Class of Stock [Line Items]
Conversion of stock (in shares)				(26,449,869)	(8,406,170)	(5,337,446)

Stock-Based Compensation_ - Nar

Stock-Based Compensation - Narrative1 (Details) - USD ($)				1 Months Ended		12 Months Ended
Stock-Based Compensation - Narrative1 (Details) - USD ($)	Nov. 30, 2023	May 31, 2023	Jan. 01, 2023	Jun. 30, 2022	Aug. 31, 2021	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense						$ 45,200,000	$ 102,800,000	$ 123,600,000
Granted (in shares)						0	0
Class A
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percent of employees' gross pay						15%
2021 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employees purchased (in shares)	627,527	601,105
Repurchase option at the original per share (in dollars per shares)	$ 2.54	$ 2.19
2021 Employee Stock Purchase Plan \| Class A
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of additional shares authorized (in shares)			1,809,383
Number of shares authorized (in shares)						8,406,337
Stock repurchase program, remaining number of shares authorized to be repurchased (in shares)						7,177,705
Annual Equity Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense						$ 11,500,000	$ 9,500,000	$ 0
2019 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)								1,277,622
2021 Stock Plan \| Class A
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of outstanding stock maximum				5%
Employee Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Purchase price of common stock, percent					85%
Percentage of outstanding stock maximum					1%
Number of additional shares authorized (in shares)					9,938,118
Total stock-based compensation expense						1,200,000	100,000
Unvested stock options						1,200,000
Options to purchase common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense						2,800,000	$ 3,800,000	$ 3,900,000
Unvested stock options						$ 4,900,000
Weighted-average period						9 months 18 days

Stock-Based Compensation_ - N_2

Stock-Based Compensation - Narrative2 (Details)		12 Months Ended
Stock-Based Compensation - Narrative2 (Details)	Sep. 16, 2021 tranche shares	Dec. 31, 2023 shares
Amended and Restated 2021 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Conversion ratio		1
Amended and Restated 2021 Plan \| Share-based Payment Arrangement, Tranche One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)		1 year
Unvested restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issued (in shares)	20,009,224	11,864,674
Holders ownership once grants are fully vested	18%
Milestone achievement period	7 years
Founder grants, number of tranches \| tranche	4
Unvested restricted stock units \| Amended and Restated 2021 Plan \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)		3 years
Unvested restricted stock units \| Amended and Restated 2021 Plan \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)		4 years
Unvested restricted stock units \| 2021 Stock Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issued (in shares)		10,866,310
Quarterly Equity Awards \| Amended and Restated 2021 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Conversion ratio		1
Quarterly Equity Awards \| Unvested restricted stock units \| Amended and Restated 2021 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issued (in shares)		998,364

Stock-Based Compensation_ - N_3

Stock-Based Compensation - Narrative3 (Details) $ in Millions						1 Months Ended	12 Months Ended
	Jul. 13, 2023 USD ($) shares	Apr. 14, 2022 shares	Apr. 13, 2022 tranche shares	Sep. 16, 2021 shares	Sep. 15, 2021 shares	Aug. 31, 2023 USD ($) shares	Dec. 31, 2023 USD ($) shares	Dec. 31, 2022 USD ($) shares	Dec. 31, 2021 USD ($) shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense \| $							$ 45.2	$ 102.8	$ 123.6
Common stock attributable to PIPE Financing (in shares)				61,512,500
Amount reclassified from legal expense to stock-based compensation expense \| $							11.6
Vendor
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Accounts payable \| $						$ 11
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense \| $							$ 16.3	$ 76.7	$ 119.9
Class B
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested (in shares)				10,004,612
Class B \| Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Forfeited (in shares)								5,002,306
Class A \| Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock attributable to PIPE Financing (in shares)						1,985,559	1,985,559		36,385,693
Unvested restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested (in shares)							7,555,232
Forfeited (in shares)							15,933,591
Shares outstanding (in shares)							31,522,483	43,146,632
Total stock-based compensation expense \| $							$ 27	$ 22.8	$ 1.6
Share-based payment arrangement, nonvested award, cost not yet recognized, amount \| $							$ 128.5
Weighted-average period							1 year
Unvested restricted stock units \| General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense \| $							$ 49.7	64.9	118.1
Unvested restricted stock units \| General and administrative \| Reversed in July 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense \| $							$ 17.3	$ 32.4	$ 9.4
Unvested restricted stock units \| Class B
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested (in shares)					5,002,306
Forfeited (in shares)		5,002,306
Shares outstanding (in shares)	15,006,918		15,006,918
Number of tranches \| tranche			3
Award vesting period (in years)	15 months		15 months
Share-based payment arrangement, reversal of expense \| $	$ 59.1
Outstanding number of shares (in shares)							15,006,918

Stock-Based Compensation_ - N_4

Stock-Based Compensation - Narrative4 (Details)			1 Months Ended	12 Months Ended
Stock-Based Compensation - Narrative4 (Details)	Aug. 09, 2022 USD ($) aircraft $ / shares shares	Jan. 29, 2021 installment milestone aircraft $ / shares shares	Aug. 31, 2023 USD ($) shares	Dec. 31, 2023 USD ($) shares	Dec. 31, 2022 USD ($) shares	Dec. 31, 2021 USD ($) shares	Sep. 16, 2021 $ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Valuation of common stock, per share (in dollars per share) \| $ / shares		$ 13.35
Valuation of common stock, PWERM weighted percentage		80%
Valuation of common stock, OPM weighted percentage		20%
Warrants price per share (in dollars per share) \| $ / shares		$ 0.01					$ 11.50
Grant date fair value (in dollars per share) \| $ / shares		$ 13.35
Number of conditional purchased aircraft \| aircraft		200
Other warrant expense \| $				$ 2,100,000	$ 10,800,000	$ 117,300,000
Class of warrant or right, vested during the period (in shares)						8,845,058
Option to purchase of additional aircraft \| aircraft		100
United
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock issued during period, shares, cashless exercised warrants (in shares) \| $			$ 2,948,352
Class A \| Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise of warrants (in shares)			2,942,778	2,942,778		8,845,058
Sub Milestone One and Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Class of warrant or right, fair value of each warrant (in dollars per share) \| $ / shares	$ 4.37
Other warrant expense \| $					$ 10,800,000
Sub Milestone Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Other warrant expense \| $				$ 2,100,000
Warrants For Collaboration Agreement With United Airlines Inc.
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Class of warrant or right, vested during the period (in shares)				2,211,264	737,088
United Airlines Inc.
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of conditional purchased aircraft \| aircraft	100
Purchase agreement, pre delivery payment received \| $	$ 10,000,000
United Airlines Inc. \| Warrants For Collaboration Agreement With United Airlines Inc.
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of vesting milestones \| milestone		4
Warrants price per share (in dollars per share) \| $ / shares		$ 0.01
Warrants, issued or issuable (in shares)		14,741,764
Number of vesting installments \| installment		4
United Airlines Inc. \| Warrants For Collaboration Agreement With United Airlines Inc. \| Class A
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of securities called by each warrant or right (in shares)		1
United Airlines Inc. \| Amended United Warrant Agreement \| Sub Milestone Three
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of conditional purchased aircraft \| aircraft	160
Class of warrant or right, vested and expected to vest (in shares)	3,685.45
United Airlines Inc. \| Amended United Warrant Agreement \| Sub Milestone Four
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of conditional purchased aircraft \| aircraft	40
Class of warrant or right, vested and expected to vest (in shares)	22,112.65
United Airlines Inc. \| Amended United Warrant Agreement \| Sub Milestone Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Class of warrant or right, vested and expected to vest (in shares)	2,211,264
United Airlines Inc. \| Amended United Warrant Agreement \| Sub Milestone One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Class of warrant or right, vested and expected to vest (in shares)	737,088

Stock-Based Compensation_ - N_5

Stock-Based Compensation - Narrative5 (Details) $ / shares in Units, $ in Millions

1 Months Ended

2 Months Ended

12 Months Ended

Aug. 10, 2023 USD ($) shares

Jun. 23, 2023 USD ($) $ / shares shares

Jan. 03, 2023 USD ($) $ / shares shares

Sep. 16, 2021 $ / shares shares

Jul. 19, 2021 installment $ / shares shares

Aug. 31, 2023 shares

Sep. 15, 2021 shares

Dec. 31, 2023 USD ($) shares

Dec. 31, 2022 USD ($) milestone shares

Dec. 31, 2021 USD ($) shares

Jan. 29, 2021 $ / shares

Nov. 06, 2020 milestone $ / shares shares

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Warrants price per share (in dollars per share)

$ 11.50

$ 0.01

Research and development | $

$ 276.4

$ 171.5

$ 64.3

Common stock attributable to PIPE Financing (in shares) | shares

61,512,500

Price per share (in dollars per share)

$ 10

Proceeds from issuance of common stock | $

Other operating income (expense), net | $

3.6

Valuation of common stock, per share (in dollars per share)

$ 13.35

Research and development warrant expense | $

$ 17.5

2.9

$ 7

Class of warrant or right, vested during the period (in shares) | shares

8,845,058

Vesting of unvested shares between July 1, 2021 and September 16, 2021 (in shares) | shares

2,540,925

Warrants For Collaboration Agreement With FCA Italy S.p.A | Research and development

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Research and development warrant expense | $

$ 2.8

Class A | Common Stock

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Common stock attributable to PIPE Financing (in shares) | shares

1,985,559

36,385,693

Stellantis N.V.

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Warrants price per share (in dollars per share)

$ 0.01

Warrants, weighted average grant date fair value (in dollars per share)

$ 1.93

Stellantis N.V. | Common Stock

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Collaborative arrangement, amount applicable to milestone | $

$ 70

Collaborative arrangement, shares applicable to milestone (in shares) | shares

12,313,234

Stellantis N.V. | Warrant Exercisable Period One

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Award vesting period (in years)

12 months

Stellantis N.V. | Warrant Exercisable Period Two

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Award vesting period (in years)

24 months

Stellantis N.V. | Warrant Exercisable Period Three

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Award vesting period (in years)

36 months

Stellantis N.V. | Warrants For Collaboration Agreement With FCA US LLC

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Research and development | $

$ 17.5

Stellantis N.V. | Class A

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Sale of stock value | $

$ 150

Number of securities called by warrants or rights (in shares) | shares

15,000,000

Share price (in dollars per share)

$ 1.93

Common stock attributable to PIPE Financing (in shares) | shares

6,337,039

Price per share (in dollars per share)

$ 3.94506

Proceeds from issuance of common stock | $

$ 25

Common stock, fair value of share issued (in dollars per share)

3.38

FCA US LLC

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Valuation of common stock, per share (in dollars per share)

$ 0.15

FCA US LLC | Warrants For Collaboration Agreement With FCA US LLC

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Number of securities called by warrants or rights (in shares) | shares

1,671,202

Warrants price per share (in dollars per share)

$ 0.01

Number of vesting milestones | milestone

Research and development warrant expense | $

$ 0.1

$ 0.2

Class of warrant or right, vested during the period (in shares) | shares

1,671,202

FCA Italy S.p.A.

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Valuation price of warrants or rights (in dollars per share)

$ 8.98

Number of vesting installments | installment

FCA Italy S.p.A. | Warrants For Collaboration Agreement With FCA Italy S.p.A

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Number of securities called by warrants or rights (in shares) | shares

1,077,024

Warrants price per share (in dollars per share)

$ 0.01

Research and development warrant expense | $

$ 6.8

Related service period

12 months

Vesting of unvested shares between July 1, 2021 and September 16, 2021 (in shares) | shares

1,077,024

Stock-Based Compensation_ - Emp

Stock-Based Compensation - Employee Stock Purchase Plan (Details) - Employee Stock	Dec. 01, 2023 $ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share price (in dollars per share)	$ 6.30
Risk-free interest rate	5.26%
Term (in years)	6 months
Volatility	97.50%
Dividend yield	0%
Grant date fair value (in dollars per share)	$ 2.62

Stock-Based Compensation_ - E_2

Stock-Based Compensation - Employee and Non Employee Stock Option (Details) - USD ($) $ / shares in Units, $ in Millions	2 Months Ended	12 Months Ended
	Sep. 15, 2021	Dec. 31, 2023	Dec. 31, 2022
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Exercised (in shares)	(4,738,344)
Employee stock options
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding period start (in shares)		5,335,974
Exercised (in shares)		(2,027,221)
Expired/forfeited (in shares)		(134,639)
Outstanding period end (in shares)		3,174,114	5,335,974
Exercisable (in shares)		1,346,269
Vested and expected to vest (in shares)		3,174,114
Weighted Average Exercise Price
Beginning Balance (in dollars per share)		$ 0.12
Exercise (in dollars per share)		0.12
Expired/forfeited (in dollars per share)		0.12
Ending Balance (in dollars per share)		0.12	$ 0.12
Exercisable, Weighted average exercise price per share (in dollars per share)		0.13
Vested and expected to vest (in dollars per share)		$ 0.12
Employee and Non Employee stock option Additional Disclosures
Weighted average remaining contractual life (in years)		6 years 7 months 28 days	7 years 7 months 28 days
Exercisable, weighted average remaining contractual term (Years)		6 years 9 months
Vested and expected, weighted average remaining contractual term (Years)		6 years 7 months 28 days
Aggregate intrinsic value		$ 19.1	$ 9.4
Exercised, aggregate intrinsic value		7.8
Exercisable as of December 31, 2023		8.1
Vested and expected, aggregate intrinsic value		$ 19.1

Stock-Based Compensation_ - Bla

Stock-Based Compensation - Black-Scholes Option (Details)	12 Months Ended
Stock-Based Compensation - Black-Scholes Option (Details)	Dec. 31, 2021 $ / shares
Employee stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	0.62%
Expected term (in years)	6 years 3 months 25 days
Volatility	87.94%
Dividend yield	0%
Grant date fair value (in dollars per share)	$ 13.65
Non-employee stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	1.08%
Expected term (in years)	10 years
Volatility	88.03%
Dividend yield	0%
Grant date fair value (in dollars per share)	$ 13.68

Stock-Based Compensation_ - Res

Stock-Based Compensation - Restricted Stock Activity (Details) - Unvested restricted stock units - $ / shares		12 Months Ended
	Sep. 16, 2021	Dec. 31, 2023
Number of Shares [Abstract]
Beginning balance (in shares)		43,146,632
Issued (in shares)	20,009,224	11,864,674
Vested (in shares)		(7,555,232)
Forfeited (in shares)		(15,933,591)
Ending Balance (in shares)		31,522,483
Weighted Average Grant Price [Abstract]
Beginning Balance (in dollars per share)		$ 5.72
Granted (in dollars per share)		3.36
Vested (in dollars per share)		3.95
Forfeited (in dollar per share)		6.26
Ending Balance (in dollars per share)		$ 4.99

Stock-Based Compensation_ - Mon

Stock-Based Compensation - Monte Carlo simulation of market award grant (Details) - Unvested restricted stock units	Sep. 16, 2021 $ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share price (in dollars per share)	$ 9.92
Term (in years)	7 years
Volatility	55%
Risk-free interest rate	1.13%
Dividend yield	0%

Stock-Based Compensation_ - Sto

Stock-Based Compensation - Stock-based Compensation Expense Included in Respective Expense Category (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 45.2	$ 102.8	$ 123.6
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	28.9	26.1	3.7
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 16.3	$ 76.7	$ 119.9

Stock-Based Compensation_ - Sch

Stock-Based Compensation - Schedule of Share-based Compensation, Warrant Activity (Details) - Warrants - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Number of Shares
Beginning balance (in shares)	8,736,599
Issued (in shares)	15,000,000
Exercised (in shares)	(2,948,352)
Ending Balance (in shares)	20,788,247	8,736,599
Vested (in shares)	2,839,893
Weighted Average Exercise Price
Beginning Balance (in dollars per share)	$ 0.01
Issued (in dollars per share)	0.01
Exercised (in dollars per share)	0.01
Ending Balance (in dollars per share)	0.01	$ 0.01
Vested (in dollars per share)	$ 0.01
Weighted Average Remaining Contractual Life (Years)
Outstanding (in years)	4 years 5 months 23 days	7 years 10 months 2 days
Vested (in years)	2 years 2 months 1 day
Aggregate Intrinsic Value (In millions)
Outstanding at period start	$ 16,300,000
Exercised	17,000,000
Outstanding at period end	127,400,000	$ 16,300,000
Vested	$ 17,400,000

Income Taxes - Schedule of Inco

Income Taxes - Schedule of Income (Loss) Before Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
United States	$ (458,700)	$ (317,300)	$ (347,800)
International	1,300	0	0
Loss before income taxes	$ (457,400)	$ (317,300)	$ (347,800)

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($)	12 Months Ended
Income Taxes - Narrative (Details) - USD ($)	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Operating Loss Carryforwards [Line Items]
Current foreign tax provision	$ 500,000
Current income tax expense (benefit)		$ 0	$ 0
Deferred income tax expense (benefit)	0	0	0
Less: valuation allowance	(226,300,000)	(129,700,000)
Valuation allowance increased	96,600,000	82,600,000	39,900,000
Unrecognized tax benefits	0	0
Income tax matters accrued interest or penalties	0	0	$ 0
Domestic Tax Authority
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	389,900,000	173,500,000
Domestic Tax Authority \| Research Tax Credit Carryforward
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount	31,400,000	14,900,000
State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	40,500,000	120,100,000
State and Local Jurisdiction \| Research Tax Credit Carryforward
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount	$ 15,700,000	$ 9,300,000

Income Taxes - Schedule Of Effe

Income Taxes - Schedule Of Effective Income Tax Rate Reconciliation (Details)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Federal income tax (benefit) at statutory tax rate	21%	21%	21%
State and local income taxes (net of federal benefit)	(2.70%)	2.50%	2.60%
Nondeductible expenses	(0.10%)	(0.20%)	(0.20%)
Warrant expense	(1.60%)	0.80%	(6.50%)
Nondeductible officers’ compensation	0.10%	(4.70%)	(6.90%)
Other	0%	(0.70%)	0.20%
Credits	4.40%	4.90%	1.30%
Change in valuation allowance	(21.20%)	(23.60%)	(11.50%)
Effective tax rate	(0.10%)	(0.00%)	(0.00%)

Income Taxes - Schedule Of Defe

Income Taxes - Schedule Of Deferred Tax Assets And Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Deferred tax assets:
Net operating loss carryforwards	$ 84.1	$ 43.4
Accrued expenses	12.4	1.5
Operating lease liabilities	3.5	3.3
Stock-based compensation	1.9	3.7
Warrants	6	2.5
Capitalized R&D expenses	77.8	51.7
Credits	41.7	21.1
Start-up costs	3.8	4.7
Other	0.7	0.9
Gross deferred tax assets	231.9	132.8
Less: valuation allowance	(226.3)	(129.7)
Deferred tax assets, net of valuation allowance	5.6	3.1
Deferred tax liabilities:
Depreciation and amortization	(3.7)	0
Right-of-use assets	(1.9)	(3.1)
Total deferred tax liabilities	(5.6)	(3.1)
Total net deferred tax assets	$ 0	$ 0

Income Taxes - Schedule of Unre

Income Taxes - Schedule of Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Changes in uncertain income tax positions
Beginning balance	$ 1.5	$ 0.3	$ 2
Increases related to current year tax positions	0.5	1.2	0.3
Decreases based on tax positions related to prior years			(2)
Ending balance	$ 2	$ 1.5	$ 0.3

Liability Classified Warrants (

Liability Classified Warrants (Details) - $ / shares	12 Months Ended
Liability Classified Warrants (Details) - $ / shares	Dec. 31, 2023	Sep. 16, 2021	Jan. 29, 2021
Class of Warrant or Right [Line Items]
Warrant outstanding (in shares)		24,666,667
Redemption price of warrants (in dollars per share)		$ 11.50	$ 0.01
Public Warrants
Class of Warrant or Right [Line Items]
Warrant outstanding (in shares)	17,398,947	16,666,667
Exercisable term from closing of initial public offering	12 months
Warrants outstanding, term	5 years
Redemption price of warrants (in dollars per share)	$ 0.01
Redemption period	30 days
Warrant redemption condition minimum share price (in dollars per share)	$ 18
Threshold trading days	20 days
Threshold consecutive trading days	30 days
Threshold number of business days before sending notice of redemption to warrant holders	3 days
Number of securities called by each warrant or right (in shares)	1
Public Warrants \| Class A
Class of Warrant or Right [Line Items]
Redemption price of warrants (in dollars per share)	$ 11.50
Private Placement Warrants
Class of Warrant or Right [Line Items]
Warrant outstanding (in shares)	8,000,000
Exercisable term after business combination	30 days