Fair Value Measurements - Summary of Financial Assets Recognized at Fair Value on Recurring Basis (Detail) - Fair Value on Recurring Basis [Member] - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Assets
Cash equivalents and restricted cash equivalents	$ 278,233	$ 534,581
Marketable securities:
Marketable securities	864,430	738,454
Total Assets	1,142,663	1,273,035
U.S. Treasury and Other Government Securities [Member]
Marketable securities:
Marketable securities	261,537	242,686
Financial Institution Debt Securities [Member]
Marketable securities:
Marketable securities	459,502	379,861
Corporate Debt Securities [Member]
Marketable securities:
Marketable securities	107,023	101,550
Other Asset Backed Securities [Member]
Marketable securities:
Marketable securities	36,368	14,357
Level 1 [Member]
Assets
Cash equivalents and restricted cash equivalents	278,233	534,581
Marketable securities:
Marketable securities	124,059	172,939
Total Assets	402,292	707,520
Level 1 [Member] | U.S. Treasury and Other Government Securities [Member]
Marketable securities:
Marketable securities	124,059	172,939
Level 2 [Member]
Marketable securities:
Marketable securities	740,371	565,515
Total Assets	740,371	565,515
Level 2 [Member] | U.S. Treasury and Other Government Securities [Member]
Marketable securities:
Marketable securities	137,478	69,747
Level 2 [Member] | Financial Institution Debt Securities [Member]
Marketable securities:
Marketable securities	459,502	379,861
Level 2 [Member] | Corporate Debt Securities [Member]
Marketable securities:
Marketable securities	107,023	101,550
Level 2 [Member] | Other Asset Backed Securities [Member]
Marketable securities:
Marketable securities	$ 36,368	$ 14,357