Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jul. 01, 2022	Jun. 30, 2023	Jul. 01, 2022
Revenues:
Revenues before reimbursements	$ 129,653	$ 118,218	$ 258,358	$ 236,088
Reimbursements	10,568	12,063	22,172	22,671
Revenues	140,221	130,281	280,530	258,759
Operating expenses:
Compensation and related expenses	82,836	58,446	167,017	127,203
Other operating expenses	10,305	8,755	19,866	16,920
Reimbursable expenses	10,568	12,063	22,172	22,671
General and administrative expenses	6,637	5,740	12,480	9,971
Total operating expenses	110,346	85,004	221,535	176,765
Operating income	29,875	45,277	58,995	81,994
Other income, net:
Interest income, net	1,593	175	3,363	196
Miscellaneous income (expense), net	4,785	(10,020)	9,433	(13,951)
Total other income, net	6,378	(9,845)	12,796	(13,755)
Income before income taxes	36,253	35,432	71,791	68,239
Income taxes	10,505	9,677	16,919	12,875
Net income	$ 25,748	$ 25,755	$ 54,872	$ 55,364
Net income per share:
Basic (in dollars per share)	$ 0.5	$ 0.5	$ 1.07	$ 1.06
Diluted (in dollars per share)	$ 0.5	$ 0.49	$ 1.06	$ 1.05
Shares used in per share computations:
Basic (in shares)	51,255	51,890	51,193	52,154
Diluted (in shares)	51,692	52,394	51,694	52,725
Cash dividends declared per common share (in dollars per share)	$ 0.26	$ 0.24	$ 0.52	$ 0.48