Collaboration and License Agreements - Schedule of Revenue from Collaboration Agreements (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue from collaboration agreements	$ 8,500	$ 8,447	$ 25,707	$ 24,933
Roche Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue from collaboration agreements	2,330	1,395	7,416	7,424
Biogen Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue from collaboration agreements	4,827	3,525	9,647	6,827
Calico Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue from collaboration agreements	$ 1,343	$ 3,527	$ 8,644	$ 10,682