| **Derivative Financial Instruments Additional Information (Details)** | Jun. 30, 2017 MBbls |
|-----------------------------------------------------------------------|---------------------|
| Crude Oil [Member]                                                    |                |
| **Derivatives in Place for Anticipated Production**                   |                |
| Anticipated crude oil production hedged (MBbls)                       | 12,896              |
| Natural Gas [Member]                                                  |                |
| **Derivatives in Place for Anticipated Production**                   |                |
| Anticipated crude oil production hedged (MBbls)                       | 82,030.2            |
| Natural Gas Liquids [Member]                                          |                |
| **Derivatives in Place for Anticipated Production**                   |                |
| Anticipated crude oil production hedged (MBbls)                       | 643                 |

| X                                                                                                                                                                                                                                                                                                                                                                                                           |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - 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**Name:**us-gaap_DerivativeLineItems**Namespace Prefix:**us-gaap_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The quantity of future oil and gas production being hedged.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 360 -Section S99 -Paragraph 2 -Subparagraph (SAB Topic 12.D.3(b)) -URI http://asc.fasb.org/extlink&oid=27015634&loc=d3e516453-122869
+ Details**Name:**us-gaap_PortionOfFutureOilAndGasProductionBeingHedged**Namespace Prefix:**us-gaap_**Data Type:**num:volumeItemType**Balance Type:**na**Period Type:**instant |
| X                                                                                                                                                                                               |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_AverageSalesPriceAndProductionCostsPerUnitOfProductionProductionTypeAxis=us-gaap_CrudeOilMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                                                                         |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_AverageSalesPriceAndProductionCostsPerUnitOfProductionProductionTypeAxis=us-gaap_NaturalGasReservesMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                                                                                |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_AverageSalesPriceAndProductionCostsPerUnitOfProductionProductionTypeAxis=us-gaap_NaturalGasLiquidsReservesMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |