Debt and Other Obligations (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Debt Instrument [Line Items]
Debt (current and long-term)	$ 134,932,000	$ 136,335,000
Capital lease obligations	275,000	446,000
Total debt	135,207,000	136,781,000
Long-term debt, current maturities	1,353,000	1,420,000
Capital lease obligations, current maturities	233,000	228,000
Current maturities of long-term obligations	1,586,000	1,648,000
Long-term debt obligations, net of current maturities	133,621,000	135,133,000
Maturity date	Dec. 31, 2019
Deferred finance charges	1,287,000
Debt issuance costs expensed	143,000
Basis spread on interest rate (in hundredths)	2.75%
Debt Instrument, Interest Rate, (Decrease)	(0.25%)
Accrued patronage refunds	722,000	707,000	529,000
Effective interest rate (in hundredths)	3.40%	4.20%	4.10%
EIS Inventory and Accounts Receivable Collateral	16,566,000
Long-term Debt, Fiscal Year Maturity [Abstract]
2014	1,353,000
2015	1,353,000
2016	1,353,000
2017	1,353,000
2018	1,353,000
Thereafter	128,167,000
Total	134,932,000	136,335,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity under credit facility	30,000,000
Term Loan B Facility [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity under credit facility	135,270,000
Periodic principal payment	$ 338,000