Income Taxes (Schedule Of Deferred Tax Assets And Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Income Taxes [Abstract]
Bad debt
Valuation allowance
Total deferred tax assets - current
Net operating loss carryforwards	9,675	8,187
Oil and gas properties	1,327	2,735
Property, Plant and Equipment		419
Property, Plant and Equipment	(163)
Asset retirement obligation	592	616
Tax credits	130	260
Miscellaneous	45	92
Valuation allowance	(11,476)	(12,067)
Total deferred tax assets - noncurrent	130	242
Net deferred tax asset	$ 130	$ 242