Benefit Plans - Funded Status (Detail) - USD ($) $ in Thousands	Dec. 30, 2018	Dec. 31, 2017	Jan. 01, 2017
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	$ 255,389	$ 257,790
Noncurrent liabilities	85,682	118,392
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	(278,957)	(303,918)	$ (273,148)
Plan assets at fair value	256,168	258,513	228,256
Net funded status	(22,789)	(45,405)
Noncurrent liabilities	22,789	45,405
Total liability - postretirement benefits	22,789	45,405
Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	(64,461)	(76,665)	(85,255)
Plan assets at fair value	0	0	$ 0
Current liabilities	3,219	3,678
Noncurrent liabilities	61,242	72,987
Total liability - postretirement benefits	$ 64,461	$ 76,665