Additional Balance Sheet and Cash Flow Information (Narrative) (Detail) (USD $)	3 Months Ended
	Mar. 30, 2014	Mar. 31, 2013
Supplemental Cash Flow Information [Abstract]
Gross unrealized gains (losses)	$ (67,000)	$ (388,000)
Gross unrealized gains (losses), net of taxes	$ (42,000)	$ (244,000)
Contractual maturities period of marketable securities, minimum (in months)	2 months
Contractual maturities period of marketable securities, maximum (in months)	26 months