Fair Value Measurements - Summary of Financial Assets Recognized at Fair Value on Recurring Basis (Detail) - Fair Value on Recurring Basis [Member] - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Assets
Cash equivalents and restricted cash equivalents	$ 150,907	$ 534,581
Marketable securities:
Marketable securities	900,281	738,454
Total Assets	1,051,188	1,273,035
U.S. Treasury and Other Government Securities [Member]
Marketable securities:
Marketable securities	368,302	242,686
Financial Institution Debt Securities [Member]
Marketable securities:
Marketable securities	417,170	379,861
Corporate Debt Securities [Member]
Marketable securities:
Marketable securities	78,942	101,550
Other Asset Backed Securities [Member]
Marketable securities:
Marketable securities	35,867	14,357
Level 1 [Member]
Assets
Cash equivalents and restricted cash equivalents	150,907	534,581
Marketable securities:
Marketable securities	117,973	172,939
Total Assets	268,880	707,520
Level 1 [Member] | U.S. Treasury and Other Government Securities [Member]
Marketable securities:
Marketable securities	117,973	172,939
Level 2 [Member]
Marketable securities:
Marketable securities	782,308	565,515
Total Assets	782,308	565,515
Level 2 [Member] | U.S. Treasury and Other Government Securities [Member]
Marketable securities:
Marketable securities	250,329	69,747
Level 2 [Member] | Financial Institution Debt Securities [Member]
Marketable securities:
Marketable securities	417,170	379,861
Level 2 [Member] | Corporate Debt Securities [Member]
Marketable securities:
Marketable securities	78,942	101,550
Level 2 [Member] | Other Asset Backed Securities [Member]
Marketable securities:
Marketable securities	$ 35,867	$ 14,357