Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurement (Details)

v3.8.0.1
Fair Value Measurement (Details)
$ in Thousands
1 Months Ended 3 Months Ended
Sep. 30, 2015
USD ($)
bbl
Mar. 31, 2018
USD ($)
Reconciliation of changes in Level 3 financial liabilities measured at fair value on a recurring basis    
Beginning balance   $ 208,014
Accretion and change in fair value   3,874
Ending balance   211,888
Level 2 | 5.375% Senior Notes due 2024    
Fair value measurement    
Debt instrument fair value   $ 651,600
Contribution Agreement | Contingent Consideration Period One    
Fair value measurement    
Contingent consideration $ 125,000  
Threshold number of barrels of water to trigger contingent consideration payment | bbl 176,295,000  
Contribution Agreement | Contingent Consideration Period Two    
Fair value measurement    
Contingent consideration $ 125,000  
Threshold number of barrels of water to trigger contingent consideration payment | bbl 219,200,000