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Supplemental Oil and Gas Disclosures - Costs Incurred in Oil and Natural Gas Property Acquisition, Exploration and Development Activities (Detail) (USD $) In Thousands, unless otherwise specified | 12 Months Ended
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Dec. 31, 2013 | Dec. 31, 2012 | Dec. 31, 2011
Supplemental Oil and Gas Disclosures [Abstract] |  |  |
Proved oil and gas properties | $ 752,454 | $ 3,159 | $ 3,356
Unproved oil and gas properties | 837,419 | 34,098 | 15,197
Exploration costs | 2,260 | 3,250 | 1,685
Development costs | 890,267 | 1,074,441 | 618,737
Asset retirement costs | 11,856 | 9,359 | 5,055
Total costs incurred | $ 2,494,256 | $ 1,124,307 | $ 644,030

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- Definition Cost incurred, including capitalized costs and costs charged to expense, in acquisition of oil and gas properties. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 18 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=8451039&loc=d3e62014-109447 + Details
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- Definition Costs incurred, including capitalized costs and costs charged to expense, associated with the acquisition of oil and gas properties that have proved reserves. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 19 -URI http://asc.fasb.org/extlink&oid=8451039&loc=d3e62038-109447 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 18 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=8451039&loc=d3e62014-109447 + Details
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- Definition Costs incurred, including capitalized costs and costs charged to expense, associated with the acquisition of oil and gas properties that have unproved reserves. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 19 -URI http://asc.fasb.org/extlink&oid=8451039&loc=d3e62038-109447 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 18 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=8451039&loc=d3e62014-109447 + Details
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- Definition Amount of asset retirement obligations (ARO) costs incurred (whether capitalized or charged to expense) during the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849 + Details
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- Definition Development costs incurred, including capitalized costs and costs charged to expense, in oil and gas activities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 18 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=8451039&loc=d3e62014-109447 + Details
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- Definition Exploration costs incurred, including capitalized costs and costs charged to expense, in oil and gas activities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Exploration -URI http://asc.fasb.org/extlink&oid=6512329 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 18 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=8451039&loc=d3e62014-109447 + Details
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