Debt (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 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		$ 5,000,000
Total interest expense	55,000	42,000	159,000	159,000
GE Credit Agreement [Member]
Line of Credit Facility [Line Items]
Revolving credit facility, aggregate amount	20,000,000		20,000,000
Payment of cash dividends allowed per year, maximum			3,500,000
Revolving credit facility, restriction on cash and cash equivalents	5,000,000		5,000,000		5,000,000
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		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%		4.25%
Minimum [Member] | Base Rate [Member] | GE Credit Agreement [Member]
Line of Credit Facility [Line Items]
Interest rate on amounts borrowed	3.25%		3.25%