Reclassification Out of Accumulated Other Comprehensive Income to Statement of Operations (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 29, 2014		Jun. 30, 2013		Jun. 29, 2014		Jun. 30, 2013
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Unrealized gains	$ 272		$ 68		$ 448		$ 212
Prior service benefit	74	[1]	69	[1]	147	[1]	138	[1]
Total reclassifications	$ 346		$ 137		$ 595		$ 350

[1] The amortization of prior service benefit is included in the computation of net periodic pension cost and postretirement benefit; see Note N: "Retirement Plans."