Benefit Plans - Reconciliation of Benefit Obligation (Detail) - Postretirement Benefits [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 29, 2019	Dec. 30, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation at beginning of year	$ 64,461	$ 76,665
Service cost	1,496	1,854	$ 2,232
Interest cost	2,750	2,694	3,636
Plan participants’ contributions	750	776
Actuarial gain	(4,191)	(14,552)
Benefits paid	(3,296)	(3,042)
Medicare Part D subsidy reimbursement	86	66
Benefit obligation at end of year	$ 62,056	$ 64,461	$ 76,665