Warrants - United Airlines (Details) $ / shares in Units, $ in Millions			3 Months Ended		8 Months Ended
	Aug. 09, 2022 USD ($) aircraft installment $ / shares shares	Jan. 29, 2021 installment aircraft milestone $ / shares shares	Mar. 31, 2026 USD ($) $ / shares shares	Mar. 31, 2025 USD ($)	Sep. 16, 2021 shares	Dec. 31, 2025 USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of conditional purchased aircraft \| aircraft		200
Option to purchase of additional aircraft \| aircraft		100
Warrants price per share (in dollars per share) \| $ / shares			$ 0.01
Class of warrant or right, vested during the period (in shares)					2,948,352
Loss on disposal of property and equipment \| $			$ 0.0	$ 0.0
First Two Milestones
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Class of warrant or right, vested during the period (in shares)			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
Class A
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Valuation of common stock, per share (in dollars per share) \| $ / shares		$ 13.35
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 \| $	$ 10.0		$ 10.0			$ 10.0
United Airlines Inc. \| Warrants For Collaboration Agreement With United Airlines Inc.
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants, issued or issuable (in shares)		14,741,764
Warrants price per share (in dollars per share) \| $ / shares		$ 0.01
Number of vesting installments \| installment	4	4
Warrants, vesting period	6 months
Number of vesting milestones \| milestone		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 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
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 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