CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Income Statement [Abstract]
Service revenues	$ 5,378,506	$ 5,795,837	$ 6,392,517
Costs of services	3,376,193	3,548,607	3,817,513
Gross margin	2,002,313	2,247,230	2,575,004
Selling, general and administrative expenses	1,925,852	2,005,756	2,110,414
Operating income	76,461	241,474	464,590
Income from investments held in employee deferred compensation trusts (which is completely offset by related costs and expenses - Note A)	(106,092)	(94,079)	(88,020)
Interest income, net	(11,799)	(22,118)	(23,973)
Income before income taxes	194,352	357,671	576,583
Provision for income taxes	61,362	106,073	165,437
Net income	$ 132,990	$ 251,598	$ 411,146
Net income per share:
Basic (usd per share)	$ 1.33	$ 2.45	$ 3.90
Diluted (usd per share)	$ 1.33	$ 2.44	$ 3.88
Weighted average shares:
Basic (in shares)	100,116	102,661	105,530
Diluted (in shares)	100,312	103,028	106,074
Dividends declared per share (in usd per share)	$ 2.36	$ 2.12	$ 1.92