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, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Segment Reporting [Line Items]
Service revenues	$ 1,336,365	$ 1,369,743	$ 2,636,544	$ 2,721,650
Segment costs of services	838,950	847,468	1,661,224	1,704,369
Compensation expenses	324,540	322,376	641,478	657,300
Other	134,296	140,705	266,579	282,076
Segment selling, general and administrative expenses	458,836	463,081	908,057	939,376
Segment income	38,579	59,194	67,263	77,905
Interest income, net	(2,013)	(2,239)	(4,771)	(5,811)
Income before income taxes	40,592	61,433	72,034	83,716
Service revenues	(1,336,365)	(1,369,743)	(2,636,544)	(2,721,650)
Contract talent solutions
Segment Reporting [Line Items]
Service revenues	747,405	759,808	1,472,421	1,523,013
Segment costs of services	454,983	462,441	898,246	928,713
Compensation expenses	210,751	209,895	417,262	430,876
Other	63,867	69,049	129,796	138,310
Segment selling, general and administrative expenses	274,618	278,944	547,058	569,186
Segment income	17,804	18,423	27,117	25,114
Service revenues	(747,405)	(759,808)	(1,472,421)	(1,523,013)
Contract talent solutions | Elimination of intersegment revenues
Segment Reporting [Line Items]
Service revenues	(121,378)	(119,812)	(238,208)	(237,709)
Service revenues	121,378	119,812	238,208	237,709
Permanent placement talent solutions
Segment Reporting [Line Items]
Service revenues	117,991	114,713	226,995	226,804
Segment costs of services	168	162	446	392
Compensation expenses	88,939	87,744	174,863	176,644
Other	17,990	18,548	34,736	37,885
Segment selling, general and administrative expenses	106,929	106,292	209,599	214,529
Segment income	10,894	8,259	16,950	11,883
Service revenues	(117,991)	(114,713)	(226,995)	(226,804)
Protiviti
Segment Reporting [Line Items]
Service revenues	470,969	495,222	937,128	971,833
Segment costs of services	383,799	384,865	762,532	775,264
Compensation expenses	24,850	24,737	49,353	49,780
Other	52,439	53,108	102,047	105,881
Segment selling, general and administrative expenses	77,289	77,845	151,400	155,661
Segment income	9,881	32,512	23,196	40,908
Service revenues	(470,969)	(495,222)	(937,128)	(971,833)
Contract Talent Solutions And Protiviti | Elimination of intersegment revenues
Segment Reporting [Line Items]
Service revenues	(121,400)	(119,800)	(238,200)	(237,700)
Service revenues	$ 121,400	$ 119,800	$ 238,200	$ 237,700