Changes in Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Dec. 26, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	$ 446,582	$ 461,221	$ 436,140
Deferred pension and other post-retirement benefit costs, net of taxes	(170)	122	130
Amortization of Deferred benefit costs, net of tax	(32)	(175)	74
Currency translation adjustment	17	(99)	(22)
Balance	423,523	446,582	461,221
AOCI Attributable to Parent
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	(1,103)	(951)	(1,133)
Currency translation adjustment	17	(99)	(22)
Balance	$ (1,288)	$ (1,103)	$ (951)