Fair Value Measurements - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021		Mar. 31, 2021	Jan. 28, 2021	Mar. 09, 2020
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value assets, transfers between Level 1, Level 2 or Level 3	$ 0		$ 0		$ 0
Fair value liabilities, transfers between Level 1, Level 2 or Level 3	0		0		0
Equity security investment	27,141,000		27,141,000		49,148,000	[1]
Gains and losses from investment in equity securities	(10,362,000)	$ (1,117,000)	(23,228,000)	$ (1,117,000)
Estimated fair value of outstanding term loan	401,200,000		401,200,000
LEO call option liability							$ 0
Gain on remeasurement of LEO call option liability				$ (5,550,000)
Other investment
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Equity security investment	16,300,000		16,300,000		18,300,000
LianBio
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Equity security investment	10,800,000		10,800,000		30,800,000
2029 Notes
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt Instrument face amount	747,500,000		747,500,000					$ 717,500,000
Estimated fair value of notes payable	302,700,000		302,700,000		444,800,000
2027 Notes
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt Instrument face amount	550,000,000.0		550,000,000.0						$ 550,000,000.0
Estimated fair value of notes payable	$ 247,500,000		$ 247,500,000		$ 407,100,000

[1] The condensed consolidated balance sheet as of December 31, 2021 is derived from the audited consolidated financial statements as of that date.