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Discontinued Operations (Schedule Of The Amounts In Net Loss From Discontinued Operations) (Details) - USD ($) $ in Thousands |  | 12 Months Ended
--- | --- | ---
Jan. 26, 2018 | Dec. 31, 2018 | Dec. 31, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] |  |  |
Discontinued operations included in current assets |  |  | $ 121
Discontinued operations included in non-current assets |  |  | 1,497
Discontinued operations included in current liabilities |  |  | 43
Net income (loss) from discontinued operations |  | $ 1,127 | 29
Sale of methane facility assets | $ 2,650 |  |
Discontinued Operations [Member] | Methane Facilities [Member] |  |  |
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] |  |  |
Accounts receivable |  |  | 91
Other current assets |  |  | 30
Discontinued operations included in current assets |  |  | 121
Property, plant, and equipment |  |  | 1,681
Accumulated depreciation, depletion, and amortization |  |  | (184)
Discontinued operations included in non-current assets |  |  | 1,497
Accounts payable - trade |  |  | 27
Accrued and other current liabilities |  |  | 16
Discontinued operations included in current liabilities |  |  | 43
Revenues |  | 6 | 580
Production costs and taxes |  | (40) | (489)
Depreciation, depletion, and amortization |  | (4) | (62)
Gain on sale of assets |  | 1,165 |
Net income (loss) from discontinued operations |  | $ 1,127 | $ 29

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