Condensed Consolidated Statements of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 28, 2012	Sep. 30, 2011	Sep. 28, 2012	Sep. 30, 2011
Revenues:
Revenues before reimbursements	$ 66,725	$ 61,387	$ 201,513	$ 186,143
Reimbursements	6,573	4,564	18,194	18,387
Revenues	73,298	65,951	219,707	204,530
Operating expenses:
Compensation and related expenses	42,589	36,051	130,621	117,259
Other operating expenses	5,908	5,858	17,422	17,344
Reimbursable expenses	6,573	4,564	18,194	18,387
General and administrative expenses	3,500	2,954	9,565	9,273
Total operating expenses	58,570	49,427	175,802	162,263
Operating income	14,728	16,524	43,905	42,267
Other income (expense), net:
Interest income, net	80	79	245	141
Miscellaneous income (expense), net	1,522	(2,203)	3,161	(669)
Total other income (expense), net	1,602	(2,124)	3,406	(528)
Income before income taxes	16,330	14,400	47,311	41,739
Income taxes	6,105	5,656	18,558	16,775
Net income	$ 10,225	$ 8,744	$ 28,753	$ 24,964
Net income per share:
Basic	$ 0.75	$ 0.63	$ 2.08	$ 1.74
Diluted	$ 0.72	$ 0.60	$ 2.01	$ 1.67
Shares used in per share computations:
Basic	13,694	13,975	13,796	14,313
Diluted	14,196	14,554	14,317	14,904