Segment Reporting - Reportable Segment Information (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Segment Reporting [Line Items]
Revenues		$ 14,658	$ 5,966	$ 24,791	$ 15,565
General and administrative	[1]	43,774	26,061	90,824	54,075
Research and development	[1]	122,365	58,035	214,104	115,899
Loss from operations		(158,118)	(79,320)	(291,075)	(157,337)
Unallocated items:
Depreciation and amortization				12,473	10,520
Stock-based compensation		14,674	4,307	38,090	11,614
Warrant expense				11,331	0
Net loss		(148,753)	(80,416)	(271,062)	(158,694)
Development and Manufacturing Electric Aircrafts
Segment Reporting [Line Items]
Revenues		14,658	5,966	24,791	15,565
Cost of revenues		6,279	1,139	10,456	2,817
Gross profit		8,379	4,827	14,335	12,748
Pre-production manufacturing		46,615	32,251	91,116	54,982
General and administrative		34,406	17,648	62,086	36,540
Research and development		31,590	19,117	58,318	47,580
Other segment items		5,578	4,205	9,871	6,758
Loss from operations		(109,810)	(68,394)	(207,056)	(133,112)
Unallocated items:
Depreciation and amortization		6,322	5,399	12,473	10,520
Stock-based compensation		14,674	4,307	38,090	11,614
Warrant expense		5,697	0	11,331	0
Other unallocated items		12,250	2,316	2,112	3,448
Net loss		$ (148,753)	$ (80,416)	$ (271,062)	$ (158,694)

[1] Includes related party amounts of $5,697 and $0 attributable to warrant expense (research and development) and $136 and $(37) (general and administrative) for the three months ended June 30, 2026 and 2025, respectively. Includes related party amounts of $11,331 and $0 attributable to warrant expense (research and development) and $223 and $(140) (general and administrative) for the six months ended June 30, 2026 and 2025, respectively (see Note 12).