Long-Term Debt (Details) (USD $)	0 Months Ended
	Aug. 20, 2012	Dec. 31, 2012	Sep. 30, 2012
Debt Instrument [Line Items]
Revolving term loan		$ 0	$ 3,237,000
Note payable to Iowa Department of Transportation		212,671	238,021
Long-term debt, total		212,671	3,475,021
Less current maturities		(25,618)	(50,968)
Long-term debt, less current maturities		187,053	3,424,053
Revolving term loan, maximum borrowing capacity	5,000,000
Debt instrument, basis spread on variable rate	3.50%
Line of credit facility, unused capacity, commitment fee percentage	0.60%
Railroad revolving loan fund		$ 500,000
Debt instrument, interest rate, stated percentage		2.11%