Derivative Instruments and Hedging Activities - Hedging Positions (Detail) - Subsequent Event [Member] - Designated as Hedging Instrument [Member]	Feb. 22, 2016 MBbls MMBTU $ / MMBTU $ / bbl
2016 Hedging Position One [Member] \| Fixed Price Swaps [Member] \| Oil (MBbls) [Member]
Derivatives, Fair Value [Line Items]
Daily Volume \| MBbls	1,000
Swap Price \| $ / bbl	49.75
2016 Hedging Position One [Member] \| Fixed Price Swaps [Member] \| Natural Gas (MMcfe) [Member]
Derivatives, Fair Value [Line Items]
Daily Volume \| MMBTU	10,000
Swap Price \| $ / MMBTU	4.110
2016 Hedging Position Two [Member] \| Fixed Price Swaps [Member] \| Oil (MBbls) [Member]
Derivatives, Fair Value [Line Items]
Daily Volume \| MBbls	1,000
Swap Price \| $ / MMBTU	52.78
2016 Hedging Position Two [Member] \| Fixed Price Swaps [Member] \| Natural Gas (MMcfe) [Member]
Derivatives, Fair Value [Line Items]
Daily Volume \| MMBTU	10,000
Swap Price \| $ / MMBTU	4.120
2016 Hedging Position Three [Member] \| Fixed Price Swaps [Member] \| Oil (MBbls) [Member]
Derivatives, Fair Value [Line Items]
Daily Volume \| MBbls	1,000
Swap Price \| $ / MMBTU	90.00
2016 Hedging Position Four [Member] \| Costless Collar [Member] \| Oil (MBbls) [Member]
Derivatives, Fair Value [Line Items]
Daily Volume \| MBbls	1,000
Floor Price \| $ / bbl	45.00
Ceiling Price \| $ / bbl	54.75

- 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

The cap rate on a price risk derivative such as a cap or collar. A payment or receipt is triggered if the market rate exceeds the cap rate on the contract.

+ References

No definition available.

+ Details

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- Definition

Floor rate on a price risk derivative such as a floor or a collar. A payment or receipt is triggered if the market rate falls below the floor rate on the contract.

+ References

No definition available.

+ Details

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- Definition

Fixed price related to the price risk swap derivative.

+ References

No definition available.

+ Details

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Details

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- Details

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- Details

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