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Related Party Transactions (Details) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Sep. 30, 2017
Sep. 30, 2016
Mar. 31, 2016
Sep. 30, 2017
Sep. 30, 2016
Nov. 05, 2015
Predecessor | Affiliated Entity            
Related Party Transaction [Line Items]            
Revenue from related parties     $ 1.4      
Black Warrior Methane (BWM)            
Related Party Transaction [Line Items]            
Proportionate consolidation method, ownership percentage           50.00%
Black Warrior Transmission (BWT)            
Related Party Transaction [Line Items]            
Equity method investment, ownership percentage           50.00%
Allocated Expenses to Joint Venture | Successor | Corporate Joint Venture            
Related Party Transaction [Line Items]            
Expenses from transactions with related party $ 1.3 $ 1.3   $ 0.5 $ 0.9  
Allocated Expenses to Joint Venture | Predecessor | Corporate Joint Venture            
Related Party Transaction [Line Items]            
Expenses from transactions with related party     $ 0.3