Organization And Accounting Policies (Assets And Liabilities Measured On Recurring Basis) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset commodity	$ 477	$ 3,520
Assets	477	3,520
SARs liability	2,532	1,007
SARs liability	624	625
Liabilities	3,156	1,632
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset commodity	477	3,520
Assets	477	3,520
SARs liability	2,532	1,007
SARs liability	624	625
Liabilities	$ 3,156	$ 1,632