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Property, Plant and Equipment - Additional Information (Detail) - USD ($) |  | 3 Months Ended | 6 Months Ended | 12 Months Ended
--- | --- | --- | --- | ---
Mar. 05, 2014 | Jun. 30, 2015 | Jun. 30, 2014 | Jun. 30, 2015 | Jun. 30, 2014 | Dec. 31, 2014
Property, Plant and Equipment [Line Items] |  |  |  |  |  |
Impairment of oil and gas properties |  | $ 19,516,000 | $ 42,000 | $ 24,837,000 | $ 804,000 |
Gain on sale of properties |  |  |  | 0 | 187,033,000 |
Unproved property leases [Member] |  |  |  |  |  |
Property, Plant and Equipment [Line Items] |  |  |  |  |  |
Impairment of oil and gas properties |  | 19,500,000 | 42,000 | 24,800,000 | 800,000 |
Impairment of oil and gas properties, periodic assessments |  | 19,100,000 |  | 20,300,000 |  |
Proved Oil And Gas Properties [Member] |  |  |  |  |  |
Property, Plant and Equipment [Line Items] |  |  |  |  |  |
Impairment of oil and gas properties |  | $ 0 | $ 0 | $ 0 | $ 0 |
Non-Operated Oil and Natural Gas Properties [Member] |  |  |  |  |  |
Property, Plant and Equipment [Line Items] |  |  |  |  |  |
Proceeds from sale of properties | $ 324,900,000 |  |  |  |  |
Gain on sale of properties |  |  |  |  |  | $ 187,000,000

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- Definition Impairment of Oil and Gas Properties, Periodic Assessments + References No definition available. + Details
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- Definition The difference between the carrying value and the sale price of real estate or properties that were intended to be sold or held for capital appreciation or rental income. This element refers to the gain (loss) included in earnings and not to the cash proceeds of the sale. This element is a noncash adjustment to net income when calculating net cash generated by operating activities using the indirect method. + 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=56944662&loc=d3e3602-108585 + Details
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- Definition The expense recorded to reduce the value of oil and gas assets consisting of proved properties and unproved properties as the estimate of future successful production from these properties is reduced. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=51719941&loc=d3e2921-110230 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 360 -Section 35 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=28370743&loc=d3e66150-109466 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3602-108585 + Details
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- Definition The cash inflow to dispose of long-lived, physical assets and mineral interests in oil and gas properties used for normal oil and gas operations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Investing Activities -URI http://asc.fasb.org/extlink&oid=6516133 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 12 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3179-108585 + 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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