Warrant Transaction Agreements - Amazon.com, Inc. Transaction Agreement (Details) $ in Millions		3 Months Ended		9 Months Ended
	Aug. 24, 2022 USD ($) $ / shares D shares	Sep. 30, 2024 USD ($) $ / shares shares	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($) $ / shares shares	Sep. 30, 2023 USD ($)	May 31, 2024 shares	Dec. 31, 2023 shares	Jun. 30, 2023 shares
Class of Warrant or Right [Line Items]
Shares of common stock that can be purchased from warrants issued (in shares) | shares						3,461,371
Tranche one of warrants issued with the Amazon.com, Inc transaction agreement | Tranche one
Class of Warrant or Right [Line Items]
Contract asset | $		$ 18.8		$ 18.8
Tranche one of warrants issued with the Amazon.com, Inc transaction agreement | Tranche two
Class of Warrant or Right [Line Items]
Contract asset | $		$ 18.8		$ 18.8
2022 Amazon transaction agreement
Class of Warrant or Right [Line Items]
Minimum percentage of warrants vested and exercisable automatically	60.00%
Shares of common stock that can be purchased from warrants issued (in shares) | shares	16,000,000
Warrant shares vested (in shares) | shares		2,500,000		2,500,000			2,000,000
Provision for common stock warrants | $			$ 1.6		$ 4.3
2022 Amazon transaction agreement | Maximum
Class of Warrant or Right [Line Items]
Shares of common stock that can be purchased from warrants issued (in shares) | shares	16,000,000
2022 Amazon transaction agreement | Warrants Tranches One Through Three
Class of Warrant or Right [Line Items]
Warrant shares vested (in shares) | shares	9,000,000
Exercise price of warrants (in dollars per share) | $ / shares	$ 22.9841
Fair value of warrants per share | $ / shares	$ 20.36
2022 Amazon transaction agreement | Warrants Tranches One Through Three | Risk-free interest rate
Class of Warrant or Right [Line Items]
Warrants and rights outstanding measurement input	3.15
2022 Amazon transaction agreement | Warrants Tranches One Through Three | Volatility
Class of Warrant or Right [Line Items]
Warrants and rights outstanding measurement input	75.00
2022 Amazon transaction agreement | Warrants Tranches One Through Three | Expected average term (years)
Class of Warrant or Right [Line Items]
Expected average term (years)	7 years
2022 Amazon transaction agreement | Warrants Tranches One Through Three | Exercise price
Class of Warrant or Right [Line Items]
Warrants and rights outstanding measurement input | $ / shares	22.98
2022 Amazon transaction agreement | Warrants Tranches One Through Three | Stock price
Class of Warrant or Right [Line Items]
Warrants and rights outstanding measurement input | $ / shares	20.36
2022 Amazon transaction agreement | Tranche one
Class of Warrant or Right [Line Items]
Warrant shares vested (in shares) | shares	1,000,000
Warrant charge capitalized | $	$ 20.4
2022 Amazon transaction agreement | Tranche two
Class of Warrant or Right [Line Items]
Warrant shares vested (in shares) | shares								1,000,000
Warrant charge capitalized | $	20.4
2022 Amazon transaction agreement | Tranche three
Class of Warrant or Right [Line Items]
Cash payments to be received under agreement | $	$ 1,000.0
Contract asset | $		$ 3.6		$ 3.6
2022 Amazon transaction agreement | Tranche four
Class of Warrant or Right [Line Items]
Warrant shares vested (in shares) | shares	7,000,000
Warrant percentage weighted average share price	90.00%
Threshold trading days | D	30
2022 Amazon transaction agreement | Tranche four | Risk-free interest rate
Class of Warrant or Right [Line Items]
Warrants and rights outstanding measurement input		3.51		3.51
2022 Amazon transaction agreement | Tranche four | Volatility
Class of Warrant or Right [Line Items]
Warrants and rights outstanding measurement input		95.00		95.00
2022 Amazon transaction agreement | Tranche four | Expected average term (years)
Class of Warrant or Right [Line Items]
Expected average term (years)				1 year 1 month 24 days
2022 Amazon transaction agreement | Tranche four | Exercise price
Class of Warrant or Right [Line Items]
Warrants and rights outstanding measurement input | $ / shares		2.03		2.03
2022 Amazon transaction agreement | Tranche four | Stock price
Class of Warrant or Right [Line Items]
Warrants and rights outstanding measurement input | $ / shares		2.26		2.26
2022 Amazon transaction agreement | Share-Based Payment Arrangement, Tranche Two
Class of Warrant or Right [Line Items]
Vesting period	7 years
Cash payments to be received under agreement | $	$ 2,100.0
Warrant shares vested (in shares) | shares	15,000,000
Warrant Issued With Amazon
Class of Warrant or Right [Line Items]
Provision for common stock warrants | $		$ 2.0		$ 4.4