Revenue Recognition - Schedule of Revenue Disaggregated by Line of Business (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Disaggregation of Revenue [Line Items]
Total service revenues	$ 1,336,365	$ 1,369,743	$ 2,636,544	$ 2,721,650
Total contract talent solutions
Disaggregation of Revenue [Line Items]
Total service revenues	747,405	759,808	1,472,421	1,523,013
Permanent placement talent solutions
Disaggregation of Revenue [Line Items]
Total service revenues	117,991	114,713	226,995	226,804
Protiviti
Disaggregation of Revenue [Line Items]
Total service revenues	470,969	495,222	937,128	971,833
Elimination of intersegment revenues | Total contract talent solutions
Disaggregation of Revenue [Line Items]
Total service revenues	(121,378)	(119,812)	(238,208)	(237,709)
Finance and accounting | Total contract talent solutions
Disaggregation of Revenue [Line Items]
Total service revenues	551,722	555,626	1,090,475	1,118,559
Administrative and customer support | Total contract talent solutions
Disaggregation of Revenue [Line Items]
Total service revenues	154,859	165,591	304,194	331,218
Technology | Total contract talent solutions
Disaggregation of Revenue [Line Items]
Total service revenues	$ 162,202	$ 158,403	$ 315,960	$ 310,945