Revenue Recognition - Schedule of Revenue Disaggregated by Line of Business (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Disaggregation of Revenue [Line Items]
Total service revenues	$ 5,378,506	$ 5,795,837	$ 6,392,517
Contract Talent Solutions
Disaggregation of Revenue [Line Items]
Total service revenues	2,990,083	3,357,872	3,895,332
Permanent Placement Talent Solutions
Disaggregation of Revenue [Line Items]
Total service revenues	439,500	487,204	567,486
Protiviti
Disaggregation of Revenue [Line Items]
Total service revenues	1,948,923	1,950,761	1,929,699
Elimination of intersegment revenues | Contract Talent Solutions
Disaggregation of Revenue [Line Items]
Total service revenues	(485,187)	(471,777)	(442,326)
Finance and accounting | Contract Talent Solutions
Disaggregation of Revenue [Line Items]
Total service revenues	2,207,152	2,454,119	2,811,093
Administration and customer support | Contract Talent Solutions
Disaggregation of Revenue [Line Items]
Total service revenues	642,939	741,468	816,409
Technology | Contract Talent Solutions
Disaggregation of Revenue [Line Items]
Total service revenues	$ 625,179	$ 634,062	$ 710,156