Marketable Securities - Summary of Fair Values and Unrealized Losses of Marketable Securities Held by the Company in an Unrealized Loss Position for Less Than 12 months and 12 Months or Greater (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Schedule Of Available For Sale Securities [Line Items]
Less than 12 Months, Fair Value	$ 495,393	$ 447,199
Less than 12 Months, Unrealized Losses	(9,617)	(1,773)
12 Months or Greater, Fair Value	72,721
12 Months or Greater, Unrealized Losses	(1,479)
Total, Fair Value	568,114	447,199
Total, Unrealized Losses	(11,096)	(1,773)
Corporate Bonds [Member]
Schedule Of Available For Sale Securities [Line Items]
Less than 12 Months, Fair Value	318,265	385,115
Less than 12 Months, Unrealized Losses	(7,503)	(1,533)
12 Months or Greater, Fair Value	72,721
12 Months or Greater, Unrealized Losses	(1,479)
Total, Fair Value	390,986	385,115
Total, Unrealized Losses	(8,982)	(1,533)
U.S. Government and Agency Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Less than 12 Months, Fair Value	173,537	59,889
Less than 12 Months, Unrealized Losses	(2,041)	(229)
Total, Fair Value	173,537	59,889
Total, Unrealized Losses	(2,041)	(229)
Certificates of Deposit [Member]
Schedule Of Available For Sale Securities [Line Items]
Less than 12 Months, Fair Value	3,591	2,195
Less than 12 Months, Unrealized Losses	(73)	(11)
Total, Fair Value	3,591	2,195
Total, Unrealized Losses	$ (73)	$ (11)