Collaboration Revenue - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended			3 Months Ended		12 Months Ended
	Nov. 30, 2017	Dec. 31, 2016	Dec. 31, 2015	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021	Dec. 31, 2018	Aug. 31, 2017
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Contract asset recorded as unbilled receivable				$ 2,000		$ 2,000
2015 Sanofi Collaboration Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaborative arrangement, rights and obligations				Sanofi has the exclusive rights and is responsible for the development, commercialization and manufacture of collaboration products resulting from the collaboration. Sanofi is obligated to use commercially reasonable efforts to commercialize at least one collaboration product for each target, within certain countries, upon regulatory approval of such product
Collaboration arrangement, initial fee paid			$ 8,000
Annual technology access and development fee		$ 9,000	$ 1,000
Remaining unrecognized revenue to be recognized								$ 3,000
Revenue, remaining performance obligation, expected timing of satisfaction, explanation				the Company had remaining unrecognized revenue of $3.0 million from the Agreement to be recognized over the remaining term (August 2017 through December 2020)
Revenue				$ 0	$ 0
Deferred revenue recognized				0		0	$ 2,000
Contract asset recorded as unbilled receivable				2,000		2,000
2017 Genentech Collaboration Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue				$ 0	$ 0	$ 1,100
Collaborative arrangement, collaboration target term	2 years
Collaboration target access fee	$ 4,500						$ 1,500