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