Equity (Details) (USD $)	12 Months Ended
	Dec. 29, 2012 item	Dec. 31, 2011	Jan. 01, 2011
Share Based Compensation
Number of plans in which awards are outstanding	5
Number of plans from which the entity has the ability to issue awards	3
Stock Options
Share Based Compensation
Maximum term for options	10 years
Number of vesting schedules	2
Annual vesting percentage under first vesting schedule	25.00%
Time period after grant date until options begin to vest (in years)	1 year
Percentage of awards vesting immediately under second vesting schedule	25.00%
Annual vesting percentage under second vesting schedule	25.00%
Options
Outstanding at the beginning of the period (in shares)	314,700
Granted (in shares)	88,800
Exercised (in shares)	(13,250)
Forfeited/Cancelled (in shares)	(54,600)
Outstanding at the end of the period (in shares)	335,650	314,700
Vested and expected to vest (in shares)	311,220
Exercisable (in shares)	207,599
Weighted Average Exercise Price Per Share
Outstanding at the beginning of the period (in dollars per share)	$ 5.11
Granted (in dollars per share)	$ 5.16
Exercised (in dollars per share)	$ 3.60
Forfeited/Cancelled (in dollars per share)	$ 4.31
Outstanding at the end of the period (in dollars per share)	$ 5.31	$ 5.11
Vested and expected to vest (in dollars per share)	$ 5.36
Exercisable (in dollars per share)	$ 5.80
Weighted Average Remaining Contractual Term
Outstanding	7 years 3 months 4 days	7 years 9 months
Vested and expected to vest	7 years 1 month 17 days
Exercisable	6 years 5 months 1 day
Aggregate Intrinsic Value
Outstanding (in dollars)	$ 34,124	$ 436,774
Vested and expected to vest (in dollars)	32,958
Exercisable (in dollars)	24,169
Additional disclosure
Total fair value of the awards vested	200,000
Total intrinsic value of awards exercised	30,000	23,000
Weighted average grant date fair value of awards granted (in dollars per share)	$ 3.17	$ 2.66	$ 1.73
Share based compensation expense	200,000	200,000
Tax benefit on share based compensation expense	11,000	12,000
Unrecognized compensation expense related to unvested option grants	$ 100,000
Weighted-average period for recognizing unrecognized share based compensation expense related to unvested stock	1 year
Weighted-average assumptions used to calculate estimated fair value of each stock option
Risk-free interest rate, Minimum (as a percent)	0.20%	0.10%	0.30%
Risk-free interest rate, Maximum (as a percent)	2.00%	2.00%	3.40%
Expected stock price volatility, Minimum (as a percent)	50.70%	65.40%	76.40%
Expected stock price volatility, Maximum (as a percent)	89.40%	96.60%	104.90%
Expected life of stock options	4 years 1 month 6 days	4 years 1 month 6 days	4 years 1 month 6 days
2000 Stock Option Plan
Share Based Compensation
Maximum awards that may be granted (in shares)	34,000
2004 Equity Incentive Plan
Share Based Compensation
Maximum awards that may be granted (in shares)	56,000
2009 Equity Incentive Plan
Share Based Compensation
Maximum awards that may be granted (in shares)	283,000