Debt (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Jan. 01, 2011
Credit Facility, Wells Fargo Bank [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 20.0
Line of credit maximum capacity for issuance letters of credit	10.0
Credit agreement, expiration date	July 1, 2012
Basis of interest rate calculation	Any borrowings under the Credit Agreement will, at our request, be classified as either LIBOR Loans or Adjusted Base Rate “ABR” Loans both as defined in the Credit Agreement. The rate of interest payable by us in respect of loans outstanding under the revolving credit facility is (i) with respect to LIBOR Loans, the Adjusted LIBO Rate as defined in the Credit Agreement for the interest period then in effect plus 3.00, or (ii) with respect to ABR Loans, the ABR as defined in the Credit Agreement then in effect plus 0.50.)
Debt covenant terms	We are subject to certain financial covenants under the Credit Agreement, including minimum fixed charge coverage ratios, maximum capital expenditure limits, minimum net worth requirements, and maintenance of an aggregate principal balance of zero under the Credit Agreement for a period of not less than 30 consecutive days in each fiscal year. The Credit Agreement is secured by a first priority security interest in our assets and those of our domestic subsidiaries.
Available remaining borrowing capacity	20.0	17.0
Adjusted LIBO Rate (in hundredths)	3.00%
ABR defined rate option, (in hundredths)	0.50%
Letters of Credit [Member]
Line of Credit Facility [Line Items]
Outstanding letters of credit		$ 3.0