Changes in Accumulated Other Comprehensive (Loss) Income (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	$ 461,221	$ 436,140	$ 302,085
Deferred pension and other post-retirement benefit costs, net of taxes	122	130	(734)
Amortization of Deferred benefit costs, net of tax	(175)	74	18
Currency translation adjustment	(99)	(22)
Balance	446,582	461,221	436,140
AOCI Attributable to Parent
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	(951)	(1,133)	(417)
Currency translation adjustment	(99)	(22)
Balance	$ (1,103)	$ (951)	$ (1,133)