Debt (Details) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Line of Credit Facility [Line Items]
Revolving credit facility, restriction on cash and cash equivalents	$ 5,000,000		$ 5,000,000
Total interest expense	50,000	65,000
GE Credit Agreement [Member]
Line of Credit Facility [Line Items]
Revolving credit facility, outstanding balance	0		0
Revolving credit facility, aggregate interest rate	6.50%		6.50%
Revolving credit facility, remaining availability	20,000,000		20,000,000
Minimum [Member] | GE Credit Agreement [Member]
Line of Credit Facility [Line Items]
Revolving credit facility, restriction on cash and cash equivalents	5,000,000
Revolving credit facility, liquidity requirement after effect to stock repurchase	20,000,000
Minimum [Member] | LIBOR Rate [Member] | GE Credit Agreement [Member]
Line of Credit Facility [Line Items]
Interest rate on amounts borrowed	4.25%
Minimum [Member] | Base Rate [Member] | GE Credit Agreement [Member]
Line of Credit Facility [Line Items]
Interest rate on amounts borrowed	3.25%
Amended [Member] | GE Credit Agreement [Member]
Line of Credit Facility [Line Items]
Revolving credit facility, aggregate amount	20,000,000
Payment of cash dividends allowed per year, maximum	$ 3,000,000