Benefit Plans - Change in Plan Assets (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at beginning of year	$ 257,790
Fair value of plan assets at end of year	255,389	$ 257,790
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at beginning of year	258,513	228,256
Actual return on plan assets	(10,242)	29,766
Employer contributions	20,000	11,600
Benefits paid	(12,103)	(11,109)
Fair value of plan assets at end of year	$ 256,168	$ 258,513