Business Segments - Reconciliation of Revenue and Operating Income by Reportable Segment to Consolidated Results (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Segment Reporting Information [Line Items]
Service revenues	$ 1,351,907	$ 1,475,937
Segment costs of services	856,901	904,783
Compensation expenses	334,925	343,668
Other	141,370	143,212
Segment selling, general and administrative expenses	476,295	486,880
Segment income	18,711	84,274
Interest income, net	(3,572)	(6,413)
Income before income taxes	22,283	90,687
Service revenues	(1,351,907)	(1,475,937)
Contract talent solutions
Segment Reporting Information [Line Items]
Service revenues	763,205	887,058
Segment costs of services	466,272	536,488
Compensation expenses	220,982	227,719
Other	69,260	72,733
Segment selling, general and administrative expenses	290,242	300,452
Segment income	6,691	50,118
Service revenues	(763,205)	(887,058)
Contract talent solutions | Elimination of intersegment revenues
Segment Reporting Information [Line Items]
Service revenues	(117,897)	(112,814)
Service revenues	117,897	112,814
Permanent placement talent solutions
Segment Reporting Information [Line Items]
Service revenues	112,091	124,767
Segment costs of services	230	219
Compensation expenses	88,900	92,322
Other	19,337	20,371
Segment selling, general and administrative expenses	108,237	112,693
Segment income	3,624	11,855
Service revenues	(112,091)	(124,767)
Protiviti
Segment Reporting Information [Line Items]
Service revenues	476,611	464,112
Segment costs of services	390,399	368,076
Compensation expenses	25,043	23,627
Other	52,773	50,108
Segment selling, general and administrative expenses	77,816	73,735
Segment income	8,396	22,301
Service revenues	(476,611)	(464,112)
Contract Talent Solutions And Protiviti | Elimination of intersegment revenues
Segment Reporting Information [Line Items]
Service revenues	(117,900)	(112,800)
Service revenues	$ 117,900	$ 112,800