Acquisitions (Fair Value of Net Assets Acquired ) (Details) - Delaware Basin [Member] - Ameredev Transaction [Member] - February 13, 2017 Acquisitions [Member] $ in Thousands |
Feb. 13, 2017
USD ($)
|
---|---|
Business Acquisition [Line Items] | |
Asset retirement obligations | $ (168) |
Net assets acquired | 632,947 |
Evaluated Oil and Natural Gas Properties [Member] | |
Business Acquisition [Line Items] | |
Oil and natural gas properties | 134,315 |
Unevaluated Oil and Natural Gas Properties [Member] | |
Business Acquisition [Line Items] | |
Oil and natural gas properties | $ 498,800 |