Financial Instruments - Schedule of Cash, Cash Equivalents and Available-for-Sale Securities by Significant Investment Category (Detail) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2022	Dec. 31, 2021
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 1,537,944	$ 1,523,467
Gross Unrealized Gains	150	719
Gross Unrealized Losses	(15,844)	(2,518)
Aggregate Fair Value	1,522,250	1,521,668
Cash and Cash Equivalents	619,802	587,276	[1]
Short-term Marketable Securities	489,945	426,599	[1]
Long-term Marketable Securities	412,503	507,793	[1]
Level 1: | Cash
Schedule of Available-for-sale Securities [Line Items]
Cash	355,318	301,177
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Aggregate Fair Value	355,318	301,177
Cash and Cash Equivalents	355,318	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	1,182,626	1,222,290
Gross Unrealized Gains	150	719
Gross Unrealized Losses	(15,844)	(2,518)
Aggregate Fair Value	1,166,932	1,220,491
Cash and Cash Equivalents	264,484	286,099
Short-term Marketable Securities	489,945	426,599
Long-term Marketable Securities	412,503	507,793
Level 2: | Money market instruments
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	264,484	285,099
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Aggregate Fair Value	264,484	285,099
Cash and Cash Equivalents	264,484	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	560,401	584,000
Gross Unrealized Gains	3	386
Gross Unrealized Losses	(12,450)	(2,086)
Aggregate Fair Value	547,954	582,300
Cash and Cash Equivalents	0	0
Short-term Marketable Securities	273,400	200,304
Long-term Marketable Securities	274,554	381,996
Level 2: | U.S. government agency securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	263,184	224,774
Gross Unrealized Gains	15	182
Gross Unrealized Losses	(2,734)	(325)
Aggregate Fair Value	260,465	224,631
Cash and Cash Equivalents	0	0
Short-term Marketable Securities	180,952	146,421
Long-term Marketable Securities	79,513	78,210
Level 2: | Commercial paper
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	33,107	68,384
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(23)	0
Aggregate Fair Value	33,084	68,384
Cash and Cash Equivalents	0	1,000
Short-term Marketable Securities	33,084	67,384
Long-term Marketable Securities	0	0
Level 2: | Asset-backed securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	58,888	56,936
Gross Unrealized Gains	8	10
Gross Unrealized Losses	(633)	(95)
Aggregate Fair Value	58,263	56,851
Cash and Cash Equivalents	0	0
Short-term Marketable Securities	0	9,451
Long-term Marketable Securities	58,263	47,400
Level 2: | Foreign and other
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	2,562	3,097
Gross Unrealized Gains	124	141
Gross Unrealized Losses	(4)	(12)
Aggregate Fair Value	2,682	3,226
Cash and Cash Equivalents	0	0
Short-term Marketable Securities	2,509	3,039
Long-term Marketable Securities	$ 173	$ 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.