Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2024	Jun. 30, 2023	Jun. 28, 2024	Jun. 30, 2023
Revenues:
Revenues before reimbursements	$ 132,434	$ 129,653	$ 269,641	$ 258,358
Reimbursements	8,102	10,568	15,828	22,172
Revenues	140,536	140,221	285,469	280,530
Operating expenses:
Compensation and related expenses	79,466	82,836	169,793	167,017
Other operating expenses	11,185	10,305	21,716	19,866
Reimbursable expenses	8,102	10,568	15,828	22,172
General and administrative expenses	6,039	6,637	11,675	12,480
Total operating expenses	104,792	110,346	219,012	221,535
Operating income	35,744	29,875	66,457	58,995
Other income, net:
Interest income, net	2,231	1,593	4,857	3,363
Miscellaneous income (expense), net	1,707	4,785	8,791	9,433
Total other income, net	3,938	6,378	13,648	12,796
Income before income taxes	39,682	36,253	80,105	71,791
Income taxes	10,455	10,505	20,736	16,919
Net income	$ 29,227	$ 25,748	$ 59,369	$ 54,872
Net income per share:
Basic (in dollars per share)	$ 0.57	$ 0.5	$ 1.16	$ 1.07
Diluted (in dollars per share)	$ 0.57	$ 0.5	$ 1.15	$ 1.06
Shares used in per share computations:
Basic (in shares)	51,111	51,255	51,059	51,193
Diluted (in shares)	51,517	51,692	51,475	51,694
Cash dividends declared per common share (in dollars per share)	$ 0.28	$ 0.26	$ 0.56	$ 0.52