Short-Term and Long-Term Debt (Details Textual) (USD $)			3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2013 Revolving line of credit [Member]	Mar. 31, 2013 Revolving line of credit [Member] Minimum
Short-Term and Long-Term Debt (Textual) [Abstract]
Line of credit amount			$ 30,000,000
Standby letter of credit			0
Interest rate on line of credit			interest rate on this line of credit can float at 2.50% over a selected LIBOR rate or can be fixed at 2.25% above LIBOR for a fixed rate term.
Credit facility maturity term			October 2013
Minimum Net Worth Required for Debt Compliance				175,000,000
Liquid assets, Debt Covenant	87,034,000	90,753,000	70,188,000	25,000,000
Tangible Net Worth			309,233,000
Current portion	$ 42,000	$ 41,000