Corporate Investments and Funds Held For Clients - Cash and Cash Equivalents and Investments (Details) - USD ($) $ in Thousands		Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023
Corporate Investments and Funds Held for Clients [Line Items]
Cash and cash equivalents, amortized cost		$ 371,325	$ 294,025
Funds held for clients cash and cash equivalents, amortized cost		2,618,450	2,128,735
Amortized cost		109,960
Total investments, amortized cost		3,099,735	2,622,647
Gross unrealized losses		(419)	(1,256)
Cash and cash equivalents, fair value		371,325	294,025	$ 505,590
Funds held for clients cash and cash equivalents, fair value		2,618,450	2,128,735
Fair value		109,541
Total investments, fair value		3,099,316
Available-for-sale Securities [Member] | U.S. Treasury Securities [Member]
Corporate Investments and Funds Held for Clients [Line Items]
Amortized cost	[1]	109,960	174,887
Gross unrealized losses	[1]	(419)	(1,256)
Fair value	[1]	$ 109,541	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.