Revenue Recognition - Schedule of Revenue Disaggregated by Line of Business (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Disaggregation of Revenue [Line Items]
Total service revenues	$ 1,354,477	$ 1,465,004	$ 4,076,127	$ 4,413,465
Total contract talent solutions
Disaggregation of Revenue [Line Items]
Total service revenues	746,223	830,403	2,269,236	2,572,358
Permanent placement talent solutions
Disaggregation of Revenue [Line Items]
Total service revenues	110,125	123,275	336,929	379,105
Protiviti
Disaggregation of Revenue [Line Items]
Total service revenues	498,129	511,326	1,469,962	1,462,002
Elimination of intersegment revenues | Total contract talent solutions
Disaggregation of Revenue [Line Items]
Total service revenues	(123,681)	(122,321)	(361,390)	(351,601)
Finance and accounting | Total contract talent solutions
Disaggregation of Revenue [Line Items]
Total service revenues	553,364	614,131	1,671,923	1,879,221
Administrative and customer support | Total contract talent solutions
Disaggregation of Revenue [Line Items]
Total service revenues	158,689	178,409	489,907	568,685
Technology | Total contract talent solutions
Disaggregation of Revenue [Line Items]
Total service revenues	$ 157,851	$ 160,184	$ 468,796	$ 476,053