Financial Instruments - Schedule of Cash, Cash Equivalents and Available-for-Sale Securities by Significant Investment Category (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 1,531,139	$ 1,523,467
Gross Unrealized Gains	246	719
Gross Unrealized Losses	(12,320)	(2,518)
Aggregate Fair Value	1,519,065	1,521,668
Cash and Cash Equivalents	605,440	587,276	[1]
Short-term Marketable Securities	450,798	426,599	[1]
Long-term Marketable Securities	462,827	507,793	[1]
Level 1: | Cash
Schedule of Available-for-sale Securities [Line Items]
Cash	441,957	301,177
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Aggregate Fair Value	441,957	301,177
Cash and Cash Equivalents	441,957	301,177
Short-term Marketable Securities	0	0
Long-term Marketable Securities	0	0
Level 2:
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,089,182	1,222,290
Gross Unrealized Gains	246	719
Gross Unrealized Losses	(12,320)	(2,518)
Aggregate Fair Value	1,077,108	1,220,491
Cash and Cash Equivalents	163,483	286,099
Short-term Marketable Securities	450,798	426,599
Long-term Marketable Securities	462,827	507,793
Level 2: | Money market instruments
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	160,485	285,099
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Aggregate Fair Value	160,485	285,099
Cash and Cash Equivalents	160,485	285,099
Short-term Marketable Securities	0	0
Long-term Marketable Securities	0	0
Level 2: | Corporate debt securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	585,315	584,000
Gross Unrealized Gains	62	386
Gross Unrealized Losses	(9,815)	(2,086)
Aggregate Fair Value	575,562	582,300
Cash and Cash Equivalents	0	0
Short-term Marketable Securities	240,777	200,304
Long-term Marketable Securities	334,785	381,996
Level 2: | U.S. government agency securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	237,962	224,774
Gross Unrealized Gains	47	182
Gross Unrealized Losses	(2,059)	(325)
Aggregate Fair Value	235,950	224,631
Cash and Cash Equivalents	0	0
Short-term Marketable Securities	155,716	146,421
Long-term Marketable Securities	80,234	78,210
Level 2: | Commercial paper
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	50,518	68,384
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(10)	0
Aggregate Fair Value	50,508	68,384
Cash and Cash Equivalents	2,998	1,000
Short-term Marketable Securities	47,510	67,384
Long-term Marketable Securities	0	0
Level 2: | Asset-backed securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	51,822	56,936
Gross Unrealized Gains	1	10
Gross Unrealized Losses	(414)	(95)
Aggregate Fair Value	51,409	56,851
Cash and Cash Equivalents	0	0
Short-term Marketable Securities	3,785	9,451
Long-term Marketable Securities	47,624	47,400
Level 2: | Foreign and other
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	3,080	3,097
Gross Unrealized Gains	136	141
Gross Unrealized Losses	(22)	(12)
Aggregate Fair Value	3,194	3,226
Cash and Cash Equivalents	0	0
Short-term Marketable Securities	3,010	3,039
Long-term Marketable Securities	$ 184	$ 187
Minimum
Schedule of Available-for-sale Securities [Line Items]
Long term marketable securities maturity period	1 year	1 year
Maximum
Schedule of Available-for-sale Securities [Line Items]
Short term marketable securities maturity period	1 year	1 year
Long term marketable securities maturity period	5 years	5 years

[1] (1)December 31, 2021 balances were derived from the audited Consolidated Financial Statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2021, filed with the SEC on February 25, 2022.