Financial Instruments Measured at Fair Value - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 27, 2014	Dec. 28, 2013
Schedule of Available-for-sale Securities [Line Items]
Variable rate demand notes maturity year	2034
Securities amortized cost, Due in one year or less	$ 1,155	$ 1,200
Securities fair value, Due in one year or less	1,155	1,200
Variable Rate Demand Notes [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities amortized cost, Due in one year or less	200
Securities fair value, Due in one year or less		$ 1,200