Consolidated Statements of Earnings and Other Comprehensive Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Revenues and reimbursable expenses:
Revenues before reimbursable expenses	$ 1,662,836	$ 1,486,085	$ 1,362,060
Reimbursable expenses	36,307	35,720	36,695
Total revenues	1,699,143	1,521,805	1,398,755
Direct Operating Costs [Abstract]
Direct costs (exclusive of depreciation and amortization included below)	1,122,429	1,010,077	942,697
Reimbursable expenses	36,301	35,715	36,766
Selling, general and administrative expenses	318,015	286,655	257,932
Other losses (gains), net	3,072	(14,196)	(444)
Restructuring charges	9,136	9,913	11,550
Depreciation and amortization	31,620	24,822	24,906
Total operating expenses	1,520,573	1,352,986	1,273,407
Operating income	178,570	168,819	125,348
Other income (expense), net
Interest expense, net of interest income	(34,197)	(25,347)	(19,573)
Other income (expense), net	(9,293)	10,544	(21,880)
Total other income (expense), net	(43,490)	(14,803)	(41,453)
Income before taxes	135,080	154,016	83,895
Income tax expense	30,040	37,390	21,416
Net income	$ 105,040	$ 116,626	$ 62,479
Net earnings per basic share:
Net income per basic share	$ 6.02	$ 6.52	$ 3.32
Net income per diluted share	$ 5.84	$ 6.27	$ 3.19
Weighted average shares used in calculating earnings per share:
Basic	17,445	17,894	18,832
Diluted	17,991	18,613	19,601
Comprehensive income
Net income	$ 105,040	$ 116,626	$ 62,479
Foreign currency translation adjustments, net of tax	1,690	(3,391)	512
Unrealized gain (loss) on investment, net of tax	(15,041)	(4,177)	7,811
Unrealized loss on cash flow hedging instruments, net of tax	(4,700)	(3,373)	(3,615)
Other comprehensive income (loss)	(18,051)	(10,941)	4,708
Comprehensive income	$ 86,989	$ 105,685	$ 67,187