Collaboration and License Agreements - Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Contract Liabilities
Contract liabilities, current	$ 9,478	$ 11,510
Contract liabilities, noncurrent	12,661	25,066
Accrued expenses, current	60,166	68,164
Collaborative Arrangement | Clementia
Contract Liabilities
Contract liabilities	0	0
Collaborative Arrangement | C Stone
Contract Liabilities
Contract liabilities	4,600	4,800
Collaborative Arrangement | Roche, Collaboration and License (Immunotherapy) Agreement
Contract Liabilities
Contract liabilities	17,564	31,405
Contract liabilities, current	4,903	6,339
Contract liabilities, noncurrent	12,661	$ 25,066
Accrued expenses	13,937
Accrued expenses, current	7,780
Accrued expenses, noncurrent	6,157
Collaborative Arrangement | Roche, Collaboration and License (Immunotherapy) Agreement, Phase I Clinical Trials
Contract Liabilities
Accrued expenses	$ 15,000