Business Segments - Schedule of Reconciliation of Revenue and Operating Income by Reportable Segment to Consolidated Results (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Segment Reporting Information [Line Items]
Service revenues	$ 1,639,478	$ 1,862,827	$ 3,355,813	$ 3,677,661
Segment income	146,612	240,531	311,406	468,182
Amortization of intangible assets	721	416	1,442	833
Interest income, net	(5,320)	(718)	(10,145)	(884)
Income before income taxes	151,211	240,833	320,109	468,233
Contract talent solutions
Segment Reporting Information [Line Items]
Service revenues	999,383	1,165,693	2,064,857	2,321,416
Segment income	81,316	133,567	183,462	266,813
Permanent placement talent solutions
Segment Reporting Information [Line Items]
Service revenues	149,254	200,096	305,991	386,878
Segment income	21,730	36,751	45,557	74,079
Protiviti
Segment Reporting Information [Line Items]
Service revenues	490,841	497,038	984,965	969,367
Segment income	$ 43,566	$ 70,213	$ 82,387	$ 127,290