License, Collaboration and Other Significant Agreements - Changes in Contract Assets and Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Contract liabilities:
Balance at End of Period	$ 42,380
Accounts receivable
Contract assets:
Balance at Beginning of Period	3,045	$ 15,822
Additions	64,676	161,772
Deductions	(48,627)	(174,549)
Balance at End of Period	19,094	3,045
Prepaid expenses and other current assets
Contract assets:
Balance at Beginning of Period	1,722	0
Additions	2,592	1,722
Deductions	(5)	0
Balance at End of Period	4,309	1,722
Deferred revenue
Contract liabilities:
Balance at Beginning of Period	40,559	72,950
Additions	83,491	122,108
Deductions	(81,670)	(154,499)
Balance at End of Period	42,380	40,559
Accounts payable
Contract liabilities:
Balance at Beginning of Period	7,227	0
Additions	3,171	17,324
Deductions	(7,227)	(10,097)
Balance at End of Period	3,171	7,227
Accrued expenses and other current liabilities
Contract liabilities:
Balance at Beginning of Period	10,000	0
Additions	0	10,615
Deductions	(10,000)	(615)
Balance at End of Period	$ 0	$ 10,000