Restructuring, Impairment and Costs of Terminated Program - Summary of Restructuring Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Restructuring Cost and Reserve [Line Items]
Clinical trial expense, other third-party and employee costs for the wind down of the bempegaldesleukin program	$ 5,492
Severance and benefit expense	7,885
Impairment of right-of-use assets and property, plant and equipment	35,328	$ 65,761	$ 0
Loss (gain) on sale or disposal of other property, plant and equipment, net	1,300	(3,326)	0
Contract termination and other restructuring costs	1,953
Restructuring, impairment and costs of terminated program	51,958	135,930	$ 0
2022 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Clinical trial expense, other third-party and employee costs for the wind down of the bempegaldesleukin program	5,492	31,693
Severance and benefit expense		30,904
Impairment of right-of-use assets and property, plant and equipment	14,728	65,761
Loss (gain) on sale or disposal of other property, plant and equipment, net	0	(3,326)
Contract termination and other restructuring costs	1,919	10,898
Restructuring, impairment and costs of terminated program	22,139	$ 135,930
2023 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Clinical trial expense, other third-party and employee costs for the wind down of the bempegaldesleukin program	0
Severance and benefit expense	7,885
Impairment of right-of-use assets and property, plant and equipment	20,600
Loss (gain) on sale or disposal of other property, plant and equipment, net	1,300
Contract termination and other restructuring costs	34
Restructuring, impairment and costs of terminated program	$ 29,819