Subject to master netting agreements (Details 4) - Discontinued operations, held-for-sale or disposed of by sale [Member] $ in Thousands	Jun. 30, 2015 USD ($)
Derivative instruments [Line Items]
Derivative asset, fair value, gross asset	$ 2,537
Derivative liability, fair value, gross liability	3,511
Commodity derivative instruments assets [Member]
Derivative instruments [Line Items]
Derivative asset, fair value, gross asset	2,537
Gross amount not offset	(2,537)
Derivative asset, fair value, net	0
Total assets [Member]
Derivative instruments [Line Items]
Derivative asset, fair value, gross asset	2,537
Gross amount not offset	(2,537)
Derivative asset, fair value, net	0
Commodity derivatives - liabilities [Member]
Derivative instruments [Line Items]
Derivative liability, fair value, gross liability	3,511
Gross amount not offset	(2,537)
Derivative liability, fair value, net	974
Total liabilities [Member]
Derivative instruments [Line Items]
Derivative liability, fair value, gross liability	3,511
Gross amount not offset	(2,537)
Derivative liability, fair value, net	$ 974

Fair value, after effects of master netting arrangements, deduction of assets not subject to a master netting arrangement and elected not to be offset, of financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, offset against an obligation to return collateral.

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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