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Description Of Business And Significant Accounting Policies (Narrative) (Details) (USD $) | 12 Months Ended |  | 12 Months Ended | 1 Months Ended | 12 Months Ended
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Dec. 31, 2012 mi | Dec. 31, 2011 | Dec. 31, 2010 | Mar. 01, 2013 | Dec. 31, 2012 Customer A [Member] | Dec. 31, 2011 Customer A [Member] | Dec. 31, 2010 Customer A [Member] | Dec. 31, 2012 Customer B [Member] | Dec. 31, 2011 Customer B [Member] | Dec. 31, 2010 Customer B [Member] | Dec. 31, 2012 Customer C [Member] | Dec. 31, 2011 Customer C [Member] | Dec. 31, 2010 Customer C [Member] | Dec. 31, 2012 Pipeline [Member] | Dec. 31, 2010 Pipeline [Member] | Jun. 30, 2012 Methane Facilities [Member] | Dec. 31, 2012 Methane Facilities [Member] | Dec. 31, 2011 Methane Facilities [Member] | Dec. 31, 2010 Methane Facilities [Member] | Dec. 31, 2012 Other Property And Equipment [Member] | Dec. 31, 2011 Other Property And Equipment [Member] | Dec. 31, 2010 Other Property And Equipment [Member] | Dec. 31, 2012 Minimum [Member] | Dec. 31, 2012 Minimum [Member] Other Property And Equipment [Member] | Dec. 31, 2012 Maximum [Member] | Dec. 31, 2012 Maximum [Member] Other Property And Equipment [Member]
Description Of Business And Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Length of pipeline, miles | 65 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Certificate of Deposit to cover future asset retirement obligations | $ 120,500 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collateral for a bond to appeal a civil penalty | 386,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Unevaluated properties | 457,000 | 268,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Current cost discount | 10.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Estimated useful life |  |  |  |  |  |  |  |  |  |  |  |  |  | 30 years |  |  | 32 years 9 months |  |  |  |  |  |  | 2 years |  | 7 years
Impairment |  |  |  |  |  |  |  |  |  |  |  |  |  | 5,200,000 | 5,000,000 |  |  |  |  |  |  |  |  |  |  |
Impairment net of tax |  |  |  |  |  |  |  |  |  |  |  |  |  | 3,400,000 | 3,300,000 |  |  |  |  |  |  |  |  |  |  |
Book value of property | 1,813,000 | 1,822,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Depreciation expense |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 100,000 | 100,000 | 200,000 | 200,000 | 200,000 |  |  |  |
Cash payment in lieu of tax credits |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1,000,000 |  |  |  |  |  |  |  |  |  |
Period of ineligibility after tax credit incentive award date | 5 years |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Compensation expense | 52,000 | 165,000 | 111,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Federal net operating loss carryforwards | 21,800,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Federal net operating loss carryforwards expiration between, years | 2019 and 2031 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2019 |  | 2031 |
Deferred tax asset | 9,434,000 | 10,241,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Customer's percentage of revenue |  |  |  |  | 84.00% | 83.50% | 80.00% | 14.30% | 13.90% | 16.60% | 2.20% | 1.90% | 2.30% |  |  |  |  |  |  |  |  |  |  |  |  |
Sale price of Swan Creek and Pipeline assets |  |  |  | $ 1,500,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |

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