Short-Term Investments - Summary of Estimated Fair Value of Short-Term Investments (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Cash Cash Equivalents And Short Term Investments [Line Items]
Amortized Cost	$ 553,254	$ 390,254
Gross Unrealized Gain	15	86
Gross Unrealized Loss	(639)	(17)
Estimated Fair Value	552,630	390,323
U.S. Treasury securities
Cash Cash Equivalents And Short Term Investments [Line Items]
Amortized Cost	222,206	143,244
Gross Unrealized Gain	0	12
Gross Unrealized Loss	(482)	(2)
Estimated Fair Value	221,724	143,254
Commercial paper
Cash Cash Equivalents And Short Term Investments [Line Items]
Amortized Cost	218,391	108,892
Gross Unrealized Gain	14	5
Gross Unrealized Loss	(24)	(1)
Estimated Fair Value	218,381	108,896
Corporate debt securities
Cash Cash Equivalents And Short Term Investments [Line Items]
Amortized Cost	58,881	85,788
Gross Unrealized Gain	0	48
Gross Unrealized Loss	(45)	(13)
Estimated Fair Value	58,836	85,823
U.S. Government-sponsored enterprises
Cash Cash Equivalents And Short Term Investments [Line Items]
Amortized Cost	50,773	52,330
Gross Unrealized Gain	1	21
Gross Unrealized Loss	(88)	(1)
Estimated Fair Value	50,686	$ 52,350
Supranational bonds
Cash Cash Equivalents And Short Term Investments [Line Items]
Amortized Cost	3,003
Gross Unrealized Gain	0
Gross Unrealized Loss	0
Estimated Fair Value	$ 3,003