Components of Net Periodic Pension Expense (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 30, 2013	Mar. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 211	$ 241
Interest cost	290	238
Expected return on plan assets	(306)	(265)
Amortization of actuarial loss and prior service costs	274	287
Net periodic pension cost	$ 469	$ 501