Components of Reclassifications from Accumulated Other Comprehensive Income (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 28, 2013		Sep. 28, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amortization of actuarial loss and prior service costs-total before tax	$ (274)	[1],[2]	$ (822)	[1],[2]
Tax benefit	102	[1]	306	[1]
Net of tax	$ (172)	[1]	$ (516)	[1]

[1] Amounts in parenthesis indicate reductions to net income upon reclassification from accumulated other comprehensive loss.

[2] The amount is included in the computation of net periodic pension cost.