Fair Value Measurements - Fair Value of Financial Assets by Level (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Assets, Fair Value Disclosure [Abstract]
Cash Equivalents:	$ 1,455,266	$ 1,017,704
Marketable Securities:	4,253,249
Total Financial Assets	5,709,914	4,087,924
Debt Securities, Available-for-Sale, Fair Value to Amortized Cost, after Allowance for Credit Loss [Abstract]
Amortized Cost	4,315,416	3,063,694
Unrealized Gains	21,410	6,827
Unrealized Losses	(697)	(4,160)
Fair Value	4,336,129	3,066,361
Marketable securities
Assets, Fair Value Disclosure [Abstract]
Marketable securities	4,253,249	3,069,362
Commercial paper
Assets, Fair Value Disclosure [Abstract]
Marketable Securities:	25,058	0
Debt Securities, Available-for-Sale, Fair Value to Amortized Cost, after Allowance for Credit Loss [Abstract]
Amortized Cost	28,052	1,999
Unrealized Gains	0	0
Unrealized Losses	0	0
Fair Value	28,052	1,999
Certificates of deposits
Assets, Fair Value Disclosure [Abstract]
Marketable Securities:	0	5,000
U.S. government notes
Assets, Fair Value Disclosure [Abstract]
Marketable Securities:	1,506,033	1,044,859
Debt Securities, Available-for-Sale, Fair Value to Amortized Cost, after Allowance for Credit Loss [Abstract]
Amortized Cost	1,554,054	1,043,445
Unrealized Gains	7,088	2,874
Unrealized Losses	(220)	(1,460)
Fair Value	1,560,922	1,044,859
Corporate bonds
Assets, Fair Value Disclosure [Abstract]
Marketable Securities:	1,968,281	1,362,124
Debt Securities, Available-for-Sale, Fair Value to Amortized Cost, after Allowance for Credit Loss [Abstract]
Amortized Cost	1,957,674	1,361,132
Unrealized Gains	10,854	2,810
Unrealized Losses	(247)	(1,818)
Fair Value	1,968,281	1,362,124
Agency securities
Assets, Fair Value Disclosure [Abstract]
Marketable Securities:	753,877	657,379
Debt Securities, Available-for-Sale, Fair Value to Amortized Cost, after Allowance for Credit Loss [Abstract]
Amortized Cost	775,636	657,118
Unrealized Gains	3,468	1,143
Unrealized Losses	(230)	(882)
Fair Value	778,874	657,379
Money market funds - restricted
Assets, Fair Value Disclosure [Abstract]
Money market funds - restricted	1,399	858
Money market funds
Assets, Fair Value Disclosure [Abstract]
Cash Equivalents:	1,372,386	1,015,705
Commercial paper
Assets, Fair Value Disclosure [Abstract]
Cash Equivalents:	2,994	1,999
U.S. government notes
Assets, Fair Value Disclosure [Abstract]
Cash Equivalents:	54,889	0
Agency securities
Assets, Fair Value Disclosure [Abstract]
Cash Equivalents:	24,997	0
Level I
Assets, Fair Value Disclosure [Abstract]
Cash Equivalents:	1,427,275	1,015,705
Total Financial Assets	2,934,707	2,061,422
Level I \| Marketable securities
Assets, Fair Value Disclosure [Abstract]
Marketable securities	1,506,033	1,044,859
Level I \| Commercial paper
Assets, Fair Value Disclosure [Abstract]
Marketable Securities:	0	0
Level I \| Certificates of deposits
Assets, Fair Value Disclosure [Abstract]
Marketable Securities:	0	0
Level I \| U.S. government notes
Assets, Fair Value Disclosure [Abstract]
Marketable Securities:	1,506,033	1,044,859
Level I \| Corporate bonds
Assets, Fair Value Disclosure [Abstract]
Marketable Securities:	0	0
Level I \| Agency securities
Assets, Fair Value Disclosure [Abstract]
Marketable Securities:	0	0
Level I \| Money market funds - restricted
Assets, Fair Value Disclosure [Abstract]
Money market funds - restricted	1,399	858
Level I \| Money market funds
Assets, Fair Value Disclosure [Abstract]
Cash Equivalents:	1,372,386	1,015,705
Level I \| Commercial paper
Assets, Fair Value Disclosure [Abstract]
Cash Equivalents:	0	0
Level I \| U.S. government notes
Assets, Fair Value Disclosure [Abstract]
Cash Equivalents:	54,889	0
Level I \| Agency securities
Assets, Fair Value Disclosure [Abstract]
Cash Equivalents:	0	0
Level II
Assets, Fair Value Disclosure [Abstract]
Cash Equivalents:	27,991	1,999
Total Financial Assets	2,775,207	2,026,502
Level II \| Marketable securities
Assets, Fair Value Disclosure [Abstract]
Marketable securities	2,747,216	2,024,503
Level II \| Commercial paper
Assets, Fair Value Disclosure [Abstract]
Marketable Securities:	25,058	0
Level II \| Certificates of deposits
Assets, Fair Value Disclosure [Abstract]
Marketable Securities:	0	5,000
Level II \| U.S. government notes
Assets, Fair Value Disclosure [Abstract]
Marketable Securities:	0	0
Level II \| Corporate bonds
Assets, Fair Value Disclosure [Abstract]
Marketable Securities:	1,968,281	1,362,124
Level II \| Agency securities
Assets, Fair Value Disclosure [Abstract]
Marketable Securities:	753,877	657,379
Level II \| Money market funds - restricted
Assets, Fair Value Disclosure [Abstract]
Money market funds - restricted	0	0
Level II \| Money market funds
Assets, Fair Value Disclosure [Abstract]
Cash Equivalents:	0	0
Level II \| Commercial paper
Assets, Fair Value Disclosure [Abstract]
Cash Equivalents:	2,994	1,999
Level II \| U.S. government notes
Assets, Fair Value Disclosure [Abstract]
Cash Equivalents:	0	0
Level II \| Agency securities
Assets, Fair Value Disclosure [Abstract]
Cash Equivalents:	24,997	0
Level III
Assets, Fair Value Disclosure [Abstract]
Cash Equivalents:	0	0
Total Financial Assets	0	0
Level III \| Marketable securities
Assets, Fair Value Disclosure [Abstract]
Marketable securities	0	0
Level III \| Commercial paper
Assets, Fair Value Disclosure [Abstract]
Marketable Securities:	0	0
Level III \| Certificates of deposits
Assets, Fair Value Disclosure [Abstract]
Marketable Securities:	0	0
Level III \| U.S. government notes
Assets, Fair Value Disclosure [Abstract]
Marketable Securities:	0	0
Level III \| Corporate bonds
Assets, Fair Value Disclosure [Abstract]
Marketable Securities:	0	0
Level III \| Agency securities
Assets, Fair Value Disclosure [Abstract]
Marketable Securities:	0	0
Level III \| Money market funds - restricted
Assets, Fair Value Disclosure [Abstract]
Money market funds - restricted	0	0
Level III \| Money market funds
Assets, Fair Value Disclosure [Abstract]
Cash Equivalents:	0	0
Level III \| Commercial paper
Assets, Fair Value Disclosure [Abstract]
Cash Equivalents:	0	0
Level III \| U.S. government notes
Assets, Fair Value Disclosure [Abstract]
Cash Equivalents:	0	0
Level III \| Agency securities
Assets, Fair Value Disclosure [Abstract]
Cash Equivalents:	$ 0	$ 0

Cash, Cash Equivalents And Available-For-Sale Debt Securities, Amortized Cost

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Cash, Cash Equivalents, And Marketable Securities

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Fair value portion of asset recognized for present right to economic benefit.

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Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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