Benefit Plans - Reconciliation of Benefit Obligation (Detail) - Postretirement Benefits [Member] - USD ($) $ in Thousands	12 Months Ended
	Jan. 01, 2017	Jan. 03, 2016	Dec. 28, 2014
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation at beginning of year	$ 70,361	$ 70,121
Service cost	1,567	1,118	$ 1,445
Interest cost	3,094	2,878	3,255
Acquisition of benefits	3,458
Plan participants’ contributions	662	594
Actuarial (gain)/loss	9,152	(1,600)
Benefits paid	(3,135)	(2,886)
Medicare Part D subsidy reimbursement	96	136
Benefit obligation at end of year	$ 85,255	$ 70,361	$ 70,121