Shareholders' Equity (Details 2) (Stock options, USD $)	3 Months Ended
	Mar. 30, 2013
Shareholders' Equity
Options Outstanding (in shares)	1,009,500
Weighted Average Remaining Contractual Life	6 years 10 months 24 days
Weighted Average Exercise Price (in dollars per share)	$ 3.59
Options Exercisable (in shares)	423,700
Weighted Average Exercise Price (in dollars per share)	$ 2.57
Range of exercise price per share from $1.59 to $1.86
Shareholders' Equity
Exercise price, low end of range (in dollars per share)	$ 1.59
Exercise price, high end of range (in dollars per share)	$ 1.86
Options Outstanding (in shares)	261,100
Weighted Average Remaining Contractual Life	5 years 1 month 2 days
Weighted Average Exercise Price (in dollars per share)	$ 1.75
Options Exercisable (in shares)	177,600
Weighted Average Exercise Price (in dollars per share)	$ 1.76
Range of exercise price per share from $2.26 to $3.44
Shareholders' Equity
Exercise price, low end of range (in dollars per share)	$ 2.26
Exercise price, high end of range (in dollars per share)	$ 3.44
Options Outstanding (in shares)	330,200
Weighted Average Remaining Contractual Life	6 years 2 months 16 days
Weighted Average Exercise Price (in dollars per share)	$ 2.87
Options Exercisable (in shares)	181,600
Weighted Average Exercise Price (in dollars per share)	$ 2.81
Range of exercise price per share from $3.60 to $6.55
Shareholders' Equity
Exercise price, low end of range (in dollars per share)	$ 3.60
Exercise price, high end of range (in dollars per share)	$ 6.55
Options Outstanding (in shares)	413,200
Weighted Average Remaining Contractual Life	8 years 6 months 14 days
Weighted Average Exercise Price (in dollars per share)	$ 5.27
Options Exercisable (in shares)	64,500
Weighted Average Exercise Price (in dollars per share)	$ 4.15
Range of exercise price per share from $7.38to $7.38
Shareholders' Equity
Exercise price, low end of range (in dollars per share)	$ 7.38
Exercise price, high end of range (in dollars per share)	$ 7.38
Options Outstanding (in shares)	5,000
Weighted Average Remaining Contractual Life	9 years 11 months 1 day
Weighted Average Exercise Price (in dollars per share)	$ 7.38