Restructuring Charges - Charges Related to the Restructuring Activities (Details) - USD ($) $ in Thousands		3 Months Ended			9 Months Ended
	Jun. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Jun. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Restructuring Cost and Reserve [Line Items]
Severance Related Expenses			$ 0			$ 6,400
Stock-based compensation expense		$ 13,100	4,785		$ 35,617	8,405
Loss on Disposal of Long Lived Assets					0	915
Lease Asset Impairment	$ 900
Research and Development Expense
Restructuring Cost and Reserve [Line Items]
Stock-based compensation expense		8,555	2,965		18,863	4,136
Loss on Disposal of Long Lived Assets				$ 700
General and administrative
Restructuring Cost and Reserve [Line Items]
Stock-based compensation expense		$ 4,545	$ 1,820		$ 16,754	$ 4,269
Loss on Disposal of Long Lived Assets				200
Restructuring Activities
Restructuring Cost and Reserve [Line Items]
Severance Related Expenses				6,448
Stock-based compensation expense				993
Loss on Disposal of Long Lived Assets				931
Lease Asset Impairment				2,580
Total Restructuring Costs				10,952
Restructuring Activities | Research and Development Expense
Restructuring Cost and Reserve [Line Items]
Severance Related Expenses				3,182
Stock-based compensation expense				123
Loss on Disposal of Long Lived Assets				749
Lease Asset Impairment				1,405
Total Restructuring Costs				5,459
Restructuring Activities | General and administrative
Restructuring Cost and Reserve [Line Items]
Severance Related Expenses				3,266
Stock-based compensation expense				870
Loss on Disposal of Long Lived Assets				182
Lease Asset Impairment				1,175
Total Restructuring Costs				$ 5,493