Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions	1 Months Ended
	Oct. 31, 2021	Feb. 29, 2020	Nov. 30, 2019	Mar. 31, 2019	Dec. 31, 2021	Dec. 31, 2020
Class Of Stock [Line Items]
Common stock issued		2.5	0.3
Common stock fair value		$ 312,100			$ 9	$ 8
Common stock average price per share	$ 81.00			$ 140.41
Net proceeds from issue of common stock	$ 548,500			$ 365,400
Issuance costs	$ 26,500			$ 300
Roche Holding A.G. [Member]
Class Of Stock [Line Items]
Direct Transaction Fees		$ 4,300
StrideBio, Inc. [Member]
Class Of Stock [Line Items]
Common stock fair value			$ 29,400
Underwritten Public Offering [Member]
Class Of Stock [Line Items]
Common stock issued	7.1			2.6