Revenue Recognition - Schedule of Revenue Disaggregated by Line of Business (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2025 USD ($) segment	Mar. 31, 2024 USD ($)
Revenue from Contract with Customer [Abstract]
Number of reportable segments | segment	3
Guarantee period	90 days
Disaggregation of Revenue [Line Items]
Total service revenues	$ 1,351,907	$ 1,475,937
Total contract talent solutions
Disaggregation of Revenue [Line Items]
Total service revenues	763,205	887,058
Permanent placement talent solutions
Disaggregation of Revenue [Line Items]
Total service revenues	112,091	124,767
Protiviti
Disaggregation of Revenue [Line Items]
Total service revenues	476,611	464,112
Elimination of intersegment revenues | Total contract talent solutions
Disaggregation of Revenue [Line Items]
Total service revenues	(117,897)	(112,814)
Finance and accounting | Total contract talent solutions
Disaggregation of Revenue [Line Items]
Total service revenues	562,933	641,970
Administrative and customer support | Total contract talent solutions
Disaggregation of Revenue [Line Items]
Total service revenues	165,627	199,932
Technology | Total contract talent solutions
Disaggregation of Revenue [Line Items]
Total service revenues	$ 152,542	$ 157,970