Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2023	Sep. 30, 2022	Sep. 29, 2023	Sep. 30, 2022
Revenues:
Revenues before reimbursements	$ 124,959	$ 115,143	$ 383,317	$ 351,231
Reimbursements	8,377	12,036	30,549	34,707
Revenues	133,336	127,179	413,866	385,938
Operating expenses:
Compensation and related expenses	74,011	62,779	241,028	189,982
Other operating expenses	10,997	8,822	30,863	25,742
Reimbursable expenses	8,377	12,036	30,549	34,707
General and administrative expenses	6,018	6,729	18,498	16,700
Total operating expenses	99,403	90,366	320,938	267,131
Operating income	33,933	36,813	92,928	118,807
Other income, net:
Interest income, net	1,858	638	5,221	834
Miscellaneous income (expense), net	(1,774)	(3,975)	7,659	(17,926)
Total other income (expense), net	84	(3,337)	12,880	(17,092)
Income before income taxes	34,017	33,476	105,808	101,715
Income taxes	9,479	9,034	26,398	21,909
Net income	$ 24,538	$ 24,442	$ 79,410	$ 79,806
Net income per share:
Basic (in dollars per share)	$ 0.48	$ 0.47	$ 1.55	$ 1.54
Diluted (in dollars per share)	$ 0.48	$ 0.47	$ 1.54	$ 1.52
Shares used in per share computations:
Basic (in shares)	51,203	51,492	51,197	51,934
Diluted (in shares)	51,645	52,008	51,680	52,489
Cash dividends declared per common share (in dollars per share)	$ 0.26	$ 0.24	$ 0.78	$ 0.72