Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 29, 2018	Jun. 30, 2017	Jun. 29, 2018	Jun. 30, 2017
Revenues:
Revenues before reimbursements	$ 89,972	$ 84,120	$ 180,656	$ 164,587
Reimbursements	5,649	3,720	11,422	7,375
Revenues	95,621	87,840	192,078	171,962
Operating expenses:
Compensation and related expenses	55,458	51,536	113,037	105,954
Other operating expenses	7,566	7,275	15,031	14,466
Reimbursable expenses	5,649	3,720	11,422	7,375
General and administrative expenses	4,470	4,992	8,512	9,216
Total operating expenses	73,143	67,523	148,002	137,011
Operating income	22,478	20,317	44,076	34,951
Other income, net:
Interest income, net	543	266	1,073	500
Miscellaneous income, net	1,898	1,765	2,220	4,307
Total other income, net	2,441	2,031	3,293	4,807
Income before income taxes	24,919	22,348	47,369	39,758
Income taxes	6,494	8,557	8,604	9,391
Net income	$ 18,425	$ 13,791	$ 38,765	$ 30,367
Net income per share:
Basic	$ 0.35	$ 0.26	$ 0.73	$ 0.58
Diluted	$ 0.34	$ 0.26	$ 0.72	$ 0.56
Shares used in per share computations:
Basic	53,008	52,830	52,876	52,716
Diluted	54,195	53,936	54,111	53,960
Cash dividends declared per common share	$ 0.13	$ 0.105	$ 0.26	$ 0.21