CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Income Statement [Abstract]
Service revenues	$ 1,354,477	$ 1,465,004	$ 4,076,127	$ 4,413,465
Costs of services	850,246	893,348	2,563,377	2,702,333
Gross margin	504,231	571,656	1,512,750	1,711,132
Selling, general and administrative expenses	490,643	511,091	1,458,740	1,534,126
Operating income	13,588	60,565	54,010	177,006
Income from investments held in employee deferred compensation trusts (which is completely offset by related costs and expenses - Note A)	(47,621)	(29,230)	(85,104)	(88,339)
Interest income, net	(2,510)	(5,391)	(8,321)	(16,990)
Income before income taxes	63,719	95,186	147,435	282,335
Provision for income taxes	20,803	29,735	46,201	85,027
Net income	$ 42,916	$ 65,451	$ 101,234	$ 197,308
Net income per share:
Basic (in usd per share)	$ 0.43	$ 0.64	$ 1.01	$ 1.91
Diluted (in usd per share)	$ 0.43	$ 0.64	$ 1.01	$ 1.91
Weighted average shares:
Basic (in shares)	99,897	102,175	100,321	103,034
Diluted (in shares)	100,041	102,393	100,529	103,371
Dividends declared per share (in usd per share)	$ 0.59	$ 0.53	$ 1.77	$ 1.59