Pension and Other Post-retirement Benefits (Detail) - Amounts recognized in the consolidated balance sheets (USD $) In Thousands, unless otherwise specified	Dec. 29, 2012	Dec. 31, 2011
Deferred tax asset (liability)	$ 10,042	$ 9,403
Accumulated other comprehensive loss (income)	15,705	14,707
Pension Plans, Defined Benefit [Member]
Current liabilities
Non-current liabilities	(15,212)	(15,675)
Deferred tax asset (liability)	10,186	9,504
Accumulated other comprehensive loss (income)	15,930	14,864
Net amount recognized	10,904	8,693
Other Postretirement Benefit Plans, Defined Benefit [Member]
Current liabilities	(85)	(104)
Non-current liabilities	(471)	(617)
Deferred tax asset (liability)	(144)	(101)
Accumulated other comprehensive loss (income)	(225)	(157)
Net amount recognized	$ (925)	$ (979)