Company's Effective Tax Rate Differs From Statutory Federal Tax Rate (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jan. 01, 2016	Jan. 02, 2015	Jan. 03, 2014
Schedule Of Company Effective Tax Rate Differs From Statutory Federal Tax Rate [Line Items]
Tax at federal statutory rate	$ 24,897	$ 23,788	$ 22,381
State taxes, net of federal benefit	2,910	3,226	2,819
Tax exempt interest income	(23)	(44)	(36)
Non-deductible expenses	261	289	226
Non-deductible stock-based compensation	(42)	0	(79)
Other	(469)	5	(6)
Tax expense	$ 27,534	$ 27,264	$ 25,305
Effective tax rate	38.70%	40.10%	39.60%