Collaborations - Change in Accounts Receivable, Contract Asset and Liabilities (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2022 USD ($)
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Accounts receivable and contract assets, Beginning balance	$ 135
Accounts receivable and contract assets, Additions	1,398
Accounts receivable and contract assets, Deductions	(270)
Accounts receivable and contract assets, Ending balance	1,263
Contract Liabilities, Beginning balance	101,034
Contract Liabilities, Additions	1,263
Contract Liabilities, Deductions	(9,622)
Contract Liabilities, Ending balance	92,675
Billed Receivables - Sanofi
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Accounts receivable and contract assets, Beginning balance	0
Accounts receivable and contract assets, Additions	135
Accounts receivable and contract assets, Deductions	(135)
Accounts receivable and contract assets, Ending balance	0
Unbilled Receivables - Sanofi
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Accounts receivable and contract assets, Beginning balance	135
Accounts receivable and contract assets, Additions	1,263
Accounts receivable and contract assets, Deductions	(135)
Accounts receivable and contract assets, Ending balance	1,263
Deferred Revenue - Vertex
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Contract Liabilities, Beginning balance	19,212
Contract Liabilities, Additions
Contract Liabilities, Deductions	(2,981)
Contract Liabilities, Ending balance	16,231
Deferred Revenue - Sanofi
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Contract Liabilities, Beginning balance	81,822
Contract Liabilities, Additions	1,263
Contract Liabilities, Deductions	(6,641)
Contract Liabilities, Ending balance	$ 76,444