Consolidated Statements of Net Income and Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 28, 2019	Dec. 29, 2018	Dec. 30, 2017
Lessee, Lease, Description [Line Items]
Gross revenues	$ 508,938	$ 418,081	$ 333,034
Direct costs (excluding depreciation and amortization):
Salaries and wages	153,023	132,922	103,011
Sub-consultant services	79,598	62,218	50,171
Other direct costs	30,935	21,537	14,598
Total direct costs	263,556	216,677	167,780
Gross Profit	245,382	201,404	165,254
Operating Expenses:
Salaries and wages, payroll taxes and benefits	128,558	102,221	86,222
General and administrative	42,656	31,713	26,747
Facilities and facilities related	17,145	14,401	12,589
Depreciation and amortization	25,816	17,384	13,128
Total operating expenses	214,175	165,719	138,686
Income from operations	31,207	35,685	26,568
Interest expense	(2,275)	(1,966)	(1,935)
Income before income tax expense	28,932	33,719	24,633
Income tax expense	(5,176)	(6,863)	(627)
Net Income and Comprehensive Income	$ 23,756	$ 26,856	$ 24,006
Earnings per share:
Basic (USD per Share)	$ 1.96	$ 2.44	$ 2.36
Diluted (USD per Share)	$ 1.90	$ 2.33	$ 2.23
Weighted average common shares outstanding:
Basic (in shares)	12,116,185	10,991,124	10,178,901
Diluted (in shares)	12,513,034	11,506,466	10,777,806