Fair Value of Financial Instruments - Schedule of Fair Value of Cash Equivalents and Marketable Securities (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Marketable securities:
Fair Value	$ 504,137	$ 184,123
Cash Equivalents and Marketable Securities [Member]
Marketable securities:
Total cash equivalents and marketable securities	740,477	280,430
Corporate Bonds [Member]
Marketable securities:
Fair Value	441,321	166,292
Municipal Bonds
Marketable securities:
Fair Value		3,037
Cash Equivalents [Member]
Cash equivalents:
Total cash equivalents	236,340	96,307
US Government Agencies Debt Securities
Marketable securities:
Fair Value	59,889	12,804
Certificates of Deposit [Member]
Marketable securities:
Fair Value	2,927	1,990
Money Market Mutual Funds [Member] | Cash Equivalents [Member]
Cash equivalents:
Total cash equivalents	236,340	96,307
Significant Other Observable Inputs (Level 2) [Member]
Marketable securities:
Fair Value	504,137	184,123
Significant Other Observable Inputs (Level 2) [Member] | Cash Equivalents and Marketable Securities [Member]
Marketable securities:
Total cash equivalents and marketable securities	740,477	280,430
Significant Other Observable Inputs (Level 2) [Member] | Corporate Bonds [Member]
Marketable securities:
Fair Value	441,321	166,292
Significant Other Observable Inputs (Level 2) [Member] | Municipal Bonds
Marketable securities:
Fair Value		3,037
Significant Other Observable Inputs (Level 2) [Member] | Cash Equivalents [Member]
Cash equivalents:
Total cash equivalents	236,340	96,307
Significant Other Observable Inputs (Level 2) [Member] | US Government Agencies Debt Securities
Marketable securities:
Fair Value	59,889	12,804
Significant Other Observable Inputs (Level 2) [Member] | Certificates of Deposit [Member]
Marketable securities:
Fair Value	2,927	1,990
Significant Other Observable Inputs (Level 2) [Member] | Money Market Mutual Funds [Member] | Cash Equivalents [Member]
Cash equivalents:
Total cash equivalents	$ 236,340	$ 96,307