Financial Instruments Measured at Fair Value - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 28, 2014	Dec. 28, 2013
Investment [Line Items]
Variable rate demand notes maturity year	2034
Securities amortized cost, Due in one year or less	$ 200	$ 1,200
Securities fair value, Due in one year or less	200	1,200
Variable Rate Demand Notes [Member]
Investment [Line Items]
Securities amortized cost, Due in one year or less	200	200
Securities fair value, Due in one year or less	$ 1,200	$ 1,200