Corporate Investments and Funds Held For Clients - Cash and Cash Equivalents and Investments (Details) - USD ($) $ in Thousands		Sep. 30, 2024	Dec. 31, 2023	Sep. 30, 2023
Corporate Investments and Funds Held for Clients [Line Items]
Cash and cash equivalents, amortized cost		$ 325,757	$ 294,025
Funds held for clients cash and cash equivalents, amortized cost		1,414,723	2,128,735
Total investments, amortized cost		1,765,406	2,622,647
Gross unrealized gains		2
Gross unrealized losses			(1,256)
Cash and cash equivalents, fair value		325,757	294,025	$ 484,028
Funds held for clients cash and cash equivalents, fair value		1,414,723	2,128,735
Total investments, fair value		1,765,408	2,621,391
Available-for-sale Securities [Member] | U.S. Treasury Securities [Member]
Corporate Investments and Funds Held for Clients [Line Items]
Amortized cost	[1]	24,926	174,887
Gross unrealized gains	[1]	2
Gross unrealized losses	[1]		(1,256)
Fair value	[1]	$ 24,928	173,631
Available-for-sale Securities [Member] | Certificates of Deposit [Member]
Corporate Investments and Funds Held for Clients [Line Items]
Amortized cost	[1]		25,000
Fair value	[1]		$ 25,000

[1] All available-for-sale securities were included within the funds held for clients.