Long-Term Debt (Components Of Lease Cost) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($)
Lease Cost [Line Items]
Total operating lease cost	$ 62
Amortization of right of use assets	79
Interest on lease liabilities	5
Total finance lease cost	84
Production Costs And Taxes [Member]
Lease Cost [Line Items]
Total operating lease cost	13
General and Administrative [Member]
Lease Cost [Line Items]
Total operating lease cost	$ 49