Fair Value Measurements, Cash Equivalents and Marketable Securities - Cash Equivalents and Marketable Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023	Sep. 30, 2023
Debt Securities, Available-for-sale [Line Items]
Amortization cost, cash and cash equivalents	$ 585,022		$ 457,339
Amortized cost, cash and cash equivalents and debt securities available-for-sale	923,285	$ 1,067,608
Gross Unrealized Gain	480	0
Gross Unrealized Loss	(25)	(11)
Estimated fair value, cash, cash equivalents and debt securities	923,740	1,067,597
Money market funds
Debt Securities, Available-for-sale [Line Items]
Amortization cost, cash and cash equivalents	112,142	1,032,500
Gross Unrealized Gain	0	0
Gross Unrealized Loss	0	0
Estimated fair value, cash and cash equivalents	112,142	1,032,500
Income deposit funds
Debt Securities, Available-for-sale [Line Items]
Amortized cost, debt securities, available-for-sale	102,412
Gross Unrealized Gain	0
Gross Unrealized Loss	0
Estimated fair value, debt securities	102,412
U.S. government debt securities
Debt Securities, Available-for-sale [Line Items]
Amortized cost, debt securities, available-for-sale	708,731	35,108
Gross Unrealized Gain	480	0
Gross Unrealized Loss	(25)	(11)
Estimated fair value, debt securities	$ 709,186	$ 35,097