Long-Term Debt (Details Textuals 1) (USD $)	3 Months Ended	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2012
Letter Of Credit From Bank
Debt Instrument [Line Items]
Percentage Of Annual Fee Of Secured Amount	1.00%	1.00%
Line of Credit
Debt Instrument [Line Items]
Percentage Of Annual Fee Of Principal Amount Outstanding	0.25%	0.25%
Line of Credit | Minimum
Debt Instrument [Line Items]
increase in unsecured line of credit	$ 1,000,000	$ 1,000,000
Line of Credit | Maximum
Debt Instrument [Line Items]
increase in unsecured line of credit	2,000,000	2,000,000
Industrial Development Revenue Bonds 0.47 Percent Interest Payable 31 March 2012
Debt Instrument [Line Items]
Annual sinking fund payments commenced December 1, 2000 through 2013		170,000
Final Sinking Fund Payment Due December 1, 2014		$ 2,620,000