Represents the number of counterparties to the entity's commodity derivative contracts.

No definition available.

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- Definition

Represents the number of major counterparties, in terms of the fair value of total net fair value at the balance sheet date, that account for the specified percentage of the value of the Company's total net derivative position on the balance sheet.

+ References

No definition available.

+ Details

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- Definition

The percentage of the Company's derivative value held by its major counterparties at the balance sheet date.

+ References

No definition available.

+ Details

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- Definition

Aggregate notional amount of derivative expressed in nonmonetary units. For example, the number of barrels specified in a fuel oil forward purchase contract.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 12

-Section 13

-Sentence Column B

+ Details

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- Definition

Maximum amount of loss due to credit risk that, based on the gross fair value of the financial instrument, the entity would incur if parties to the financial instruments that make up the concentration failed completely to perform according to the terms of the contracts and the collateral or other security, if any, for the amount due proved to be of no value to the entity.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

-Paragraph 21

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=28364263&loc=d3e13537-108611

+ Details

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- Definition

Gain (loss) related to the termination of a contract between the parties. The termination may be due to many causes including early termination of a lease by a lessee, a breach of contract by one party, or a failure to perform.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 420

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (b)(1)

-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

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- Definition

Aggregate net gain (loss) on all derivative instruments recognized in earnings during the period, before tax effects.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4A

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5618551-113959

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- Definition

Amount before tax of reclassification adjustment from accumulated other comprehensive income of accumulated gain (loss) realized from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's deferred hedging gain (loss).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 11

-URI http://asc.fasb.org/extlink&oid=28358780&loc=d3e637-108580

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 15

-URI http://asc.fasb.org/extlink&oid=28358780&loc=d3e689-108580

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4

-Subparagraph c

-URI http://asc.fasb.org/extlink&oid=7476318&loc=d3e41638-113959

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Derivative Instruments (Details) (USD $)	3 Months Ended		6 Months Ended								1 Months Ended	0 Months Ended	3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended
Derivative Instruments (Details) (USD $)	Jun. 30, 2013 counterparty	Jun. 30, 2012	Jun. 30, 2013 counterparty	Jun. 30, 2012	Jun. 30, 2013 Full 2013 Term Natural Gas	Jun. 30, 2013 Full 2013 Term Crude Oil	Jun. 30, 2013 Full 2014 Term Natural Gas	Jun. 30, 2013 Full 2014 Term Crude Oil	Jun. 30, 2013 Full 2015 Term Natural Gas	Jun. 30, 2013 Full 2015 Term Crude Oil	Mar. 31, 2012 Termination of Derivatives Natural Gas	Jun. 30, 2013 Derivative	Jun. 30, 2013 Commodity Contract Realized And Unrealized Gain Loss On Derivatives Net	Jun. 30, 2012 Commodity Contract Realized And Unrealized Gain Loss On Derivatives Net	Jun. 30, 2013 Commodity Contract Realized And Unrealized Gain Loss On Derivatives Net	Jun. 30, 2012 Commodity Contract Realized And Unrealized Gain Loss On Derivatives Net	Jun. 30, 2013 Commodity Contract Oil And Natural Gas Sales	Jun. 30, 2012 Commodity Contract Oil And Natural Gas Sales	Jun. 30, 2013 Commodity Contract Sales Of Oil And Gas	Jun. 30, 2012 Commodity Contract Sales Of Oil And Gas	Jun. 30, 2013 Interest Rate Contract Interest Expense	Jun. 30, 2012 Interest Rate Contract Interest Expense	Jun. 30, 2013 Interest Rate Contract Interest Expense	Jun. 30, 2012 Interest Rate Contract Interest Expense
Derivative [Line Items]
(Gain) loss reclassified from AOCL into earnings (amortization of frozen amounts)																	$ 0	$ (2,500,000)	$ 0	$ (5,200,000)	$ 0	$ (900,000)	$ 0	$ (1,500,000)
Gain recognized in earnings (cash settlements and mark-to-market movements)	(35,622,000)	(113,082,000)	(34,885,000)	(84,601,000)									(35,622,000)	(113,082,000)	(34,885,000)	(84,601,000)
Concentration risk, credit risk, financial instrument, maximum exposure												53,200,000
Derivative, nonmonetary notional amount					10,000	19,800	0	21,000	0	3,000	15,000
Loss on contract termination											$ 1,900,000
Derivative number of counterparties to commodity contracts	9		9
Derivatives number of major counterparties	3		3
Percentage of derivative value held by major counterparties	52.00%		52.00%