Corporate Investments and Funds Held for Clients - Cash and Cash Equivalents and Investments (Details) - USD ($) $ in Thousands		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Corporate Investments and Funds Held for Clients [Line Items]
Cash and cash equivalents, amortized cost		$ 294,025	$ 400,730
Funds held for clients cash and cash equivalents, amortized cost		2,128,735	2,008,365
Amortized cost		199,887
Total investments, amortized cost		2,622,647	2,608,462
Gross unrealized losses		(1,256)	(4,757)
Cash and cash equivalents, fair value		294,025	400,730	$ 277,978
Funds held for clients cash and cash equivalents, fair value		2,128,735	2,008,365
Fair value		198,631
Total investments, fair value		2,621,391	2,603,705
Available-for-sale Securities [Member] | U.S. Treasury Securities [Member]
Corporate Investments and Funds Held for Clients [Line Items]
Amortized cost	[1]	174,887	174,367
Gross unrealized losses	[1]	(1,256)	(4,757)
Fair value	[1]	173,631	169,610
Available-for-sale Securities [Member] | Certificates of Deposit [Member]
Corporate Investments and Funds Held for Clients [Line Items]
Amortized cost	[1]	25,000	25,000
Fair value	[1]	$ 25,000	$ 25,000

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