Changes in Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 25, 2021	Dec. 26, 2020	Dec. 28, 2019
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	$ 956,967	$ 735,636	$ 460,317
Deferred pension and other post-retirement benefit costs		1,611	(442)
Amortization of Deferred benefit costs	90	(219)	(77)
Currency translation adjustment	(32)	25	47
Balance	983,409	956,967	735,636
AOCI Attributable to Parent
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	(252)	(1,669)	(1,197)
Currency translation adjustment	(32)	25	47
Balance	$ (194)	$ (252)	$ (1,669)