Debt (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011 Credit Facility, Wells Fargo Bank [Member]	Dec. 29, 2012 Amended Credit Facility, Wells Fargo Bank [Member]	Apr. 23, 2012 Amended Credit Facility, Wells Fargo Bank [Member]
Line of Credit Facility [Line Items]
Maturity date of the credit facility	Jul. 01, 2012
Amended maturity date of the credit facility		Apr. 23, 2015
Current borrowing capacity			$ 20.0
Maximum borrowing capacity			50.0
Adjusted LIBO Rate basis (in hundredths)		1.25%
Adjusted Base Rate - Daily One-Month LIBO Rate basis (in hundredths)		1.50%
Available remaining borrowing capacity	20.0	20.0
Outstanding letters of credit	$ 0	$ 0