Corporate Investments and Funds Held For Clients - Cash and Cash Equivalents and Investments (Details) - USD ($) $ in Thousands		Jun. 30, 2022	Dec. 31, 2021	Jun. 30, 2021
Corporate Investments and Funds Held for Clients [Line Items]
Cash and cash equivalents, amortized cost		$ 279,039	$ 277,978
Funds held for clients cash and cash equivalents, amortized cost		3,158,071	1,534,894
Amortized cost		267,286
Total investments, amortized cost		3,704,396	2,124,551
Gross unrealized losses	[1]	(2,176)
Cash and cash equivalents, fair value		279,039	277,978	$ 202,362
Funds held for clients cash and cash equivalents, fair value		3,158,071	1,534,894
Fair value		265,110
Total investments, fair value		3,702,220	2,124,551
Available-for-sale Securities [Member] | Commercial Paper [Member]
Corporate Investments and Funds Held for Clients [Line Items]
Amortized cost	[2]	103,094	311,679
Gross unrealized losses	[1],[2]	(517)
Fair value	[2]	102,577	$ 311,679
Available-for-sale Securities [Member] | U.S. Treasury Securities [Member]
Corporate Investments and Funds Held for Clients [Line Items]
Amortized cost	[2]	139,192
Gross unrealized losses	[1],[2]	(1,659)
Fair value	[2]	137,533
Available-for-sale Securities [Member] | Certificates of Deposit [Member]
Corporate Investments and Funds Held for Clients [Line Items]
Amortized cost	[2]	25,000
Fair value	[2]	$ 25,000

[1] These securities have been in an unrealized loss position for a period of less than 12 months.

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