Organization And Accounting Policies (Summary Of Liabilities Measured On Recurring Basis) (Details) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Derivatives, Fair Value [Line Items]
Liabilities	$ 5,175	$ 146
Fair Value, Inputs, Level 2 [Member]
Derivatives, Fair Value [Line Items]
Liabilities	2,064
Fair Value, Inputs, Level 3 [Member]
Derivatives, Fair Value [Line Items]
Liabilities	3,111	146
SARs Liability [Member]
Derivatives, Fair Value [Line Items]
Liabilities	3,111	146
SARs Liability [Member] | Fair Value, Inputs, Level 3 [Member]
Derivatives, Fair Value [Line Items]
Liabilities	3,111	$ 146
Derivative Liability Swaps [Member]
Derivatives, Fair Value [Line Items]
Liabilities	2,064
Derivative Liability Swaps [Member] | Fair Value, Inputs, Level 2 [Member]
Derivatives, Fair Value [Line Items]
Liabilities	$ 2,064