Benefit Plans - Reconciliation of Benefit Obligation (Detail) - Postretirement Benefits [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2018	Dec. 31, 2017	Jan. 01, 2017
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation at beginning of year	$ 76,665	$ 85,255
Service cost	1,854	2,232	$ 1,567
Interest cost	2,694	3,636	3,094
Plan participants’ contributions	776	752
Actuarial (gain) / loss	(14,552)	1,796
Benefits paid	(3,042)	(2,994)
Medicare Part D subsidy reimbursement	66	37
Acquisition of benefits		3,291
Divestiture of benefits related to the October 2017 Divestitures		(17,340)
Benefit obligation at end of year	$ 64,461	$ 76,665	$ 85,255