Long-Term Debt and Revolving Lines of Credit (Details) (USD $)	12 Months Ended					12 Months Ended			12 Months Ended
	Dec. 31, 2013 Facility Loan Institution	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 CoBank (term loan) [Member]	Dec. 31, 2012 CoBank (term loan) [Member]	Dec. 31, 2013 CoBank Term Loan A [Member]	Jun. 30, 2013 CoBank Term Loan A [Member]	Dec. 31, 2012 CoBank Term Loan A [Member]	Dec. 31, 2013 CoBank Term Loan A [Member] Amendment date through December 31, 2013 [Member]	Dec. 31, 2013 CoBank Term Loan A [Member] Through December 31, 2014 [Member]	Dec. 31, 2013 CoBank Term Loan A [Member] January 1, 2015 and Thereafter [Member]	Dec. 31, 2013 CoBank Term Loan A [Member] December 31, 2013 to March 31, 2014 [Member]	Dec. 31, 2013 CoBank Term Loan A [Member] April 1, 2014 through March 31, 2015 [Member]	Dec. 31, 2013 CoBank Term Loan A [Member] April 1, 2015 and Thereafter [Member]	Dec. 31, 2013 Other Debt [Member]	Dec. 31, 2012 Other Debt [Member]	Dec. 31, 2013 Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Long term debt, Total	$ 230,000,000	$ 231,977,000		$ 0	$ 1,876,000	$ 230,000,000		$ 230,000,000							$ 0	$ 101,000
Current maturities	5,750,000	1,977,000
Total long-term debt	224,250,000	230,000,000
Interest rate (in hundredths)				7.37%		2.67%
Minimum percentage of aggregate principal balance on which Entity Obtain Interest Rate Protection (in hundredths)	33.00%
Minimum days to obtain interest rate protection	90 days
Minimum time to maintain interest rate protection	3 years
Basis spread on variable rate (in hundredths)						2.50%	2.75%		0.17%
Number of Additional Farm Credit Institutions	16
Number of facilities included in Credit Agreement	3
Number of term loans included in Credit Agreement	2
Required periodic installments						5,750,000
Expected final payment						120,750,000
Maturity date						Sep. 30, 2019
Debt Instrument, Description of Variable Rate Basis						30-day LIBOR
Maximum borrowing capacity																	50,000,000
Aggregate principal amount of incremental term loan facilities, maximum	100,000,000
Trailing month basis of financial covenants						12 months
Ratio of indebtedness to EBITDA												3.00	2.50	2.00
Minimum debt service coverage ratio						2.50
Minimum equity to assets ratio									0.30	0.325	0.35
Derivative asset, fair value	4,300,000
Derivative liability, fair value		1,700,000
Percentage of principal amount of loan on which entity entered in pay fixed receive fixed interest rate swap (in hundredths)	76.00%
Derivative effective interest rate (in hundredths)	2.50%
Derivative fixed interest rate (in hundredths)	3.63%
Percentage of effective interest rate on portion of debt (in hundredths)	1.13%
Derivative, expiry date	Jul. 31, 2013
Write-off of unamortized loan fees	0	780,000	0
Aggregate maturities of long-term debt [Abstract]
2014	5,750,000
2015	23,000,000
2016	23,000,000
2017	23,000,000
2018	23,000,000
Later years	132,250,000
Long term debt, Total	230,000,000	231,977,000		0	1,876,000	230,000,000		230,000,000							0	101,000
Accured in anticipation of early 2014 distrubtion of patronage credit	$ 1,400,000
Percentage of patronage credit paid in cash (in hundredths)	75.00%
Percentage of patronage credit paid in shares (in hundredths)	25.00%