Accounts Receivable (Details 2) (Doubtful accounts, USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Jan. 02, 2012	Dec. 27, 2010
Doubtful accounts
Reserve for doubtful accounts
Balance at the beginning of the period	$ 254	$ 145	$ 116
Charged to costs and expenses	46	117	78
Deductions	3	(8)	(49)
Balance at the end of the period	$ 303	$ 254	$ 145