Other Property And Equipment (Schedule Of Other Property And Equipment) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Gross Cost	$ 342,000	$ 378,000
Accumulated depreciation	240,000	229,000
Net Book Value	102,000	149,000
Depreciation expense	75,000	79,000
Vehicles [Member]
Property, Plant and Equipment [Line Items]
Gross Cost	259,000	295,000
Accumulated depreciation	157,000	146,000
Net Book Value	102,000	149,000
Other [Member]
Property, Plant and Equipment [Line Items]
Gross Cost	83,000	83,000
Accumulated depreciation	$ 83,000	$ 83,000
Minimum [Member] | Vehicles [Member]
Property, Plant and Equipment [Line Items]
Depreciable Life	2 years	2 years
Minimum [Member] | Other [Member]
Property, Plant and Equipment [Line Items]
Depreciable Life	5 years	5 years
Maximum [Member] | Vehicles [Member]
Property, Plant and Equipment [Line Items]
Depreciable Life	3 years	3 years
Maximum [Member] | Other [Member]
Property, Plant and Equipment [Line Items]
Depreciable Life	7 years	7 years