Business Segments - Schedule of Reconciliation of Revenue and Operating Income by Reportable Segment to Consolidated Results (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Segment Reporting Information [Line Items]
Service revenues	$ 1,475,937	$ 1,716,335
Segment income	84,578	164,794
Amortization of intangible assets	304	721
Interest income, net	(6,413)	(4,825)
Income before income taxes	90,687	168,898
Contract talent solutions
Segment Reporting Information [Line Items]
Service revenues	887,058	1,065,474
Segment income	50,118	102,146
Permanent placement talent solutions
Segment Reporting Information [Line Items]
Service revenues	124,767	156,737
Segment income	11,855	23,827
Protiviti
Segment Reporting Information [Line Items]
Service revenues	464,112	494,124
Segment income	$ 22,605	$ 38,821