Deferred Charges And Liabilities (Schedule Of Deferred Charges, Or Regulatory Assets) (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Regulatory Assets [Line Items]
Total deferred charges	$ 32,764,065	$ 25,140,957
Debt Issuance And Reacquisition Costs [Member]
Regulatory Assets [Line Items]
Total regulatory assets	386,892	492,850
Refurbishment Of Transmission Equipment [Member]
Regulatory Assets [Line Items]
Total regulatory assets	95,679	104,939
Feasibility Studies [Member]
Regulatory Assets [Line Items]
Total regulatory assets	237,425	1,387,285
Cooper Lake Relicensing / Projects [Member]
Regulatory Assets [Line Items]
Total regulatory assets	5,149,903	5,280,006
Fuel Supply [Member]
Regulatory Assets [Line Items]
Total regulatory assets	1,801,970	2,005,052
Storm Damage [Member]
Regulatory Assets [Line Items]
Total regulatory assets	453,166	647,381
Other Regulatory Deferred Charges [Member]
Regulatory Assets [Line Items]
Total regulatory assets	815,722	849,933
Bond Interest - Market Risk Management [Member]
Regulatory Assets [Line Items]
Total regulatory assets	4,884,587	5,365,190
Environmental Matters [Member]
Regulatory Assets [Line Items]
Total regulatory assets	978,820	1,024,171
Beluga Parts And Materials [Member]
Regulatory Assets [Line Items]
Total regulatory assets	10,696,210	0
Regulatory Assets Excluding Other Deferred Charges [Member]
Regulatory Assets [Line Items]
Total regulatory assets	25,500,374	17,156,807
NRECA Retirement Plan [Member]
Regulatory Assets [Line Items]
Total deferred charges	7,204,591	7,925,050
Post Retirement Benefit Obligation [Member]
Regulatory Assets [Line Items]
Total deferred charges	59,100	59,100
Other Deferred Charges [Member]
Regulatory Assets [Line Items]
Total deferred charges	$ 7,263,691	$ 7,984,150