Income Taxes - Reconciliation of Income Tax Expense at Statutory Federal Rate to Actual Income Tax Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jan. 03, 2016	Dec. 28, 2014	Dec. 29, 2013
Income Tax Disclosure [Abstract]
Statutory expense	$ 34,692	$ 19,474	$ 15,485
State income taxes, net of federal benefit	3,496	2,133	1,811
Noncontrolling interest – Piedmont	(2,261)	(1,835)	(1,674)
Adjustment for uncertain tax positions	51	30	(167)
Adjustment for state tax legislation	(1,145)	0	(2,261)
Valuation allowance change	(1,332)	1,203	321
Bargain purchase gain	(704)	0	0
Capital loss carryover	0	(854)	0
Manufacturing deduction benefit	(1,330)	(1,470)	(1,995)
Meals and entertainment	1,666	1,204	1,127
Other, net	945	(349)	(505)
Income tax expense	$ 34,078	$ 19,536	$ 12,142