Income Taxes - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Operating Loss Carryforwards [Line Items]
Statutory tax rate	21.00%	21.00%	21.00%
Valuation allowance	$ 377,214,000	$ 243,811,000
Valuation allowance, increase (decrease), amount	133,400,000
Deferred tax assets, deferred expense, capitalized research and development costs	235,900,000	184,600,000
Interest and penalties accrued	0	0
Unrecognized tax benefits that would impact effective tax rate, if recognized	0
United States
Operating Loss Carryforwards [Line Items]
Valuation allowance	377,200,000	$ 243,800,000
Net operating loss carryforwards	844,300,000
Net operating loss carryforwards, not subject to expiration	801,100,000
Net operating loss carryforwards, subject to expiration	$ 43,200,000
Research and development activities, amortized over period	5 years
United States | Research Tax Credit Carryforward
Operating Loss Carryforwards [Line Items]
Research and development tax credit carryforwards	$ 26,800,000
U.S. State
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	805,300,000
U.S. State | Research Tax Credit Carryforward
Operating Loss Carryforwards [Line Items]
Research and development tax credit carryforwards	7,400,000
Tax credit carryforward, subject to expiration	600,000
Tax credit carryforward, not subject to expiration	$ 6,800,000
Foreign Tax Authority
Operating Loss Carryforwards [Line Items]
Research and development activities, amortized over period	15 years