Revenue Recognition - Schedule of Revenue Disaggregated by Line of Business (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($) segment	Mar. 31, 2022 USD ($)
Revenue from Contract with Customer [Abstract]
Number of reportable segments | segment	3
Guarantee period	90 days
Disaggregation of Revenue [Line Items]
Service revenues	$ 1,716,335	$ 1,814,834
Elimination of intersegment revenues
Disaggregation of Revenue [Line Items]
Service revenues	(125,791)	(144,200)
Finance and accounting
Disaggregation of Revenue [Line Items]
Service revenues	777,833	801,690
Administrative and customer support
Disaggregation of Revenue [Line Items]
Service revenues	219,350	284,906
Technology
Disaggregation of Revenue [Line Items]
Service revenues	194,082	213,327
Total contract talent solutions
Disaggregation of Revenue [Line Items]
Service revenues	1,065,474	1,155,723
Permanent placement talent solutions
Disaggregation of Revenue [Line Items]
Service revenues	156,737	186,782
Protiviti
Disaggregation of Revenue [Line Items]
Service revenues	$ 494,124	$ 472,329