Organization and Accounting Policies (Assets and Liabilities Measured on Recurring Basis) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset commodity		$ 636
Assets		636
SARs liability	$ 823	2,638
SARs liability	43	852
Liabilities	866	3,490
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset commodity		636
Assets		636
SARs liability	823	2,638
SARs liability	43	852
Liabilities	$ 866	$ 3,490