| Acquisitions - Fair Value of Assets Acquired (Details) - American Energy - Utica, LLC - USD ($) $ in Thousands | Jun. 29, 2015 | Jun. 12, 2015 | 
|---|---|---|
| Business Acquisition [Line Items] | ||
| Cash, net of purchase price adjustments | $ 405,000 | $ 405,029 | 
| Fair value of net identifiable assets acquired | 405,029 | |
| Proved | ||
| Business Acquisition [Line Items] | ||
| Fair value of net identifiable assets acquired | 70,804 | |
| Unevaluated | ||
| Business Acquisition [Line Items] | ||
| Fair value of net identifiable assets acquired | $ 334,225 | 
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- Definition Payment to Acquire Oil and Gas Property and Equipment, Net No definition available. 
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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. No definition available. 
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- Definition The amount of property, plant, and equipment recognized as of the acquisition date. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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