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Derivative Instruments - Schedule of Outstanding Commodity Derivative Instruments (Detail) (USD $) In Thousands, unless otherwise specified | Sep. 30, 2014
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Derivative [Line Items] |
Fair Value Asset (Liability) | $ 40,296
2014 Two-Way Collars [Member] |
Derivative [Line Items] |
Total Notional Amount of Oil (Barrels) | 1,088,000
Average Floor Price (in dollars per barrel) | 95.07
Average Ceiling Price (in dollars per barrel) | 106.42
Fair Value Asset (Liability) | 4,893
2014 Three-Way Collars [Member] |
Derivative [Line Items] |
Total Notional Amount of Oil (Barrels) | 842,000
Average Sub-Floor Price (in dollars per barrel) | 70.55
Average Floor Price (in dollars per barrel) | 90.55
Average Ceiling Price (in dollars per barrel) | 105.16
Fair Value Asset (Liability) | 1,066
2014 Swaps [Member] |
Derivative [Line Items] |
Total Notional Amount of Oil (Barrels) | 994,000
Average Swap Price (in dollars per barrel) | 96.32
Fair Value Asset (Liability) | 3,942
2014 Swaps with sub-floors [Member] |
Derivative [Line Items] |
Total Notional Amount of Oil (Barrels) | 552,000
Average Swap Price (in dollars per barrel) | 92.60
Average Sub-Floor Price (in dollars per barrel) | 70.00
Fair Value Asset (Liability) | 690
2015 Two-Way Collars [Member] |
Derivative [Line Items] |
Total Notional Amount of Oil (Barrels) | 2,388,500
Average Floor Price (in dollars per barrel) | 87.98
Average Ceiling Price (in dollars per barrel) | 103.21
Fair Value Asset (Liability) | 9,574
2015 Three-Way Collars [Member] |
Derivative [Line Items] |
Total Notional Amount of Oil (Barrels) | 263,500
Average Sub-Floor Price (in dollars per barrel) | 70.59
Average Floor Price (in dollars per barrel) | 90.59
Average Ceiling Price (in dollars per barrel) | 105.25
Fair Value Asset (Liability) | 869
2015 Swaps [Member] |
Derivative [Line Items] |
Total Notional Amount of Oil (Barrels) | 5,263,500
Average Swap Price (in dollars per barrel) | 90.81
Fair Value Asset (Liability) | 14,093
2015 Swaps with sub-floors [Member] |
Derivative [Line Items] |
Total Notional Amount of Oil (Barrels) | 186,000
Average Swap Price (in dollars per barrel) | 92.60
Average Sub-Floor Price (in dollars per barrel) | 70.00
Fair Value Asset (Liability) | 538
2015 Deferred Premium Puts [Member] |
Derivative [Line Items] |
Total Notional Amount of Oil (Barrels) | 1,086,000
Average Floor Price (in dollars per barrel) | 90.00
Average deferred premium (in dollars per barrel) | 2.55
Fair Value Asset (Liability) | 2,919
2016 Two Way Collars [Member] |
Derivative [Line Items] |
Total Notional Amount of Oil (Barrels) | 155,000
Average Floor Price (in dollars per barrel) | 86.00
Average Ceiling Price (in dollars per barrel) | 103.42
Fair Value Asset (Liability) | 692
2016 Swaps [Member] |
Derivative [Line Items] |
Total Notional Amount of Oil (Barrels) | 310,000
Average Swap Price (in dollars per barrel) | 90.15
Fair Value Asset (Liability) | $ 1,020

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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 The average strike price of the sold put that establishes the price at which if the market price falls below, the minimum price would be index price plus the difference between the purchased put (floor) and the sold put strike price. + References No definition available. + Details
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- Definition The average cap rate on a group of price risk derivatives such as caps or collars. 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 The average floor rate on a group of price risk derivatives such as floors or collars. 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 Fair value of the assets less the liabilities of a derivative or group of derivatives. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=35750535&loc=d3e13433-108611 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41228-113958 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=35750535&loc=d3e13495-108611 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 45 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41271-113958 + Details
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- Definition Average fixed price related to the group of price risk swap derivatives. + References No definition available. + Details
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