CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Income Statement [Abstract]
Service revenues	$ 1,369,743	$ 1,472,524	$ 2,721,650	$ 2,948,461
Costs of services	860,269	895,845	1,713,131	1,808,985
Gross margin	509,474	576,679	1,008,519	1,139,476
Selling, general and administrative expenses	507,934	501,136	968,097	1,023,035
Operating income	1,540	75,543	40,422	116,441
Income from investments held in employee deferred compensation trusts (which is completely offset by related costs and expenses - Note A)	(57,654)	(15,733)	(37,483)	(59,109)
Interest income, net	(2,239)	(5,186)	(5,811)	(11,599)
Income before income taxes	61,433	96,462	83,716	187,149
Provision for income taxes	20,465	28,306	25,398	55,292
Net income	$ 40,968	$ 68,156	$ 58,318	$ 131,857
Net income per share:
Basic (in usd per share)	$ 0.41	$ 0.66	$ 0.58	$ 1.27
Diluted (in usd per share)	$ 0.41	$ 0.66	$ 0.58	$ 1.27
Weighted average shares:
Basic (in shares)	100,410	103,151	100,537	103,469
Diluted (in shares)	100,539	103,328	100,776	103,864
Dividends declared per share (in usd per share)	$ 0.59	$ 0.53	$ 1.18	$ 1.06