Deferred Charges And Liabilities (Schedule Of Deferred Charges, Or Regulatory Assets, Not Currently Being Recovered In Rates Charged To Consumers) (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Regulatory Assets [Line Items]
Total deferred charges	$ 32,764,065	$ 25,140,957
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 Regulatory Deferred Charges [Member]
Regulatory Assets [Line Items]
Total regulatory assets	815,722	849,933
Not Currently Being Recovered In Rates Charged to Consumers [Member]
Regulatory Assets [Line Items]
Total deferred charges	260,875	9,148,731
Not Currently Being Recovered In Rates Charged to Consumers [Member] | Multi-Stage Energy Storage [Member]
Regulatory Assets [Line Items]
Total regulatory assets	0	1,117,860
Not Currently Being Recovered In Rates Charged to Consumers [Member] | Regulatory Studies And Other [Member]
Regulatory Assets [Line Items]
Total regulatory assets	201,775	46,721
Not Currently Being Recovered In Rates Charged to Consumers [Member] | Regulatory Assets Excluding Other Deferred Charges [Member]
Regulatory Assets [Line Items]
Total regulatory assets	201,775	1,164,581
Not Currently Being Recovered In Rates Charged to Consumers [Member] | NRECA Retirement Plan [Member]
Regulatory Assets [Line Items]
Total deferred charges	0	7,925,050
Not Currently Being Recovered In Rates Charged to Consumers [Member] | Post Retirement Benefit Obligation [Member]
Regulatory Assets [Line Items]
Total deferred charges	59,100	59,100
Not Currently Being Recovered In Rates Charged to Consumers [Member] | Other Regulatory Deferred Charges [Member]
Regulatory Assets [Line Items]
Total deferred charges	$ 59,100	$ 7,984,150