Revenue Recognition - Schedule of Revenue Disaggregated by Line of Business (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($) segment	Jun. 30, 2022 USD ($)
Revenue from Contract with Customer [Abstract]
Number of reportable segments | segment			3
Guarantee period			90 days
Disaggregation of Revenue [Line Items]
Total service revenues	$ 1,639,478	$ 1,862,827	$ 3,355,813	$ 3,677,661
Elimination of intersegment revenues
Disaggregation of Revenue [Line Items]
Total service revenues	(114,807)	(137,548)	(240,598)	(281,748)
Finance and accounting
Disaggregation of Revenue [Line Items]
Total service revenues	721,391	810,910	1,499,224	1,612,600
Administrative and customer support
Disaggregation of Revenue [Line Items]
Total service revenues	211,023	274,141	430,373	559,047
Technology
Disaggregation of Revenue [Line Items]
Total service revenues	181,776	218,190	375,858	431,517
Total contract talent solutions
Disaggregation of Revenue [Line Items]
Total service revenues	999,383	1,165,693	2,064,857	2,321,416
Permanent placement talent solutions
Disaggregation of Revenue [Line Items]
Total service revenues	149,254	200,096	305,991	386,878
Protiviti
Disaggregation of Revenue [Line Items]
Total service revenues	$ 490,841	$ 497,038	$ 984,965	$ 969,367