Short-Term and Long-Term Debt (Details Textual) (USD $)			6 Months Ended
	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2013 Revolving line of credit	Jun. 30, 2013 Revolving line of credit 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
Tangible net worth			309,860,000
Liquid assets, debt covenant	$ 94,539,000	$ 90,753,000	$ 75,394,000	$ 25,000,000