Debt (Schedule Of Maturities Of Long-Term Obligations) (Details)	Dec. 31, 2016 USD ($)
Debt Instrument [Line Items]
2017	$ 24,836,667
2018	24,608,667
2019	24,608,667
2020	24,836,667
2021	18,064,667
Thereafter	353,487,330
Total long-term obligations	470,442,665
2011 Series A Bonds [Member]
Debt Instrument [Line Items]
2017	10,666,667
2018	10,666,667
2019	10,666,667
2020	10,666,667
2021	10,666,667
Thereafter	168,333,330
Total long-term obligations	221,666,665
2011 CoBank Note [Member]
Debt Instrument [Line Items]
2017	3,420,000
2018	3,192,000
2019	3,192,000
2020	3,420,000
2021	3,648,000
Thereafter	26,904,000
Total long-term obligations	43,776,000
2012 Series A Bonds [Member]
Debt Instrument [Line Items]
2017	10,750,000
2018	10,750,000
2019	10,750,000
2020	10,750,000
2021	3,750,000
Thereafter	158,250,000
Total long-term obligations	$ 205,000,000