Financial Instruments Measured at Fair Value - Additional Information (Detail) (USD $)	3 Months Ended	9 Months Ended
	Sep. 28, 2013	Sep. 28, 2013	Sep. 28, 2013 Variable rate demand notes [Member]	Dec. 29, 2012 Variable rate demand notes [Member]
Investment [Line Items]
Variable rate demand notes maturity year	2037	2037
Securities amortized cost, Due in one year or less			$ 1,200,000	$ 1,200,000
Securities fair value, Due in one year or less			1,500,000	1,500,000
Derivative instrument gain (loss), current net income	$ 44,000	$ (300,000)