Derivative Instruments - Gain (Loss) On Derivative Instruments (Details) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended 12 Months Ended
Dec. 31, 2016
Oct. 10, 2016
Dec. 31, 2018
Dec. 31, 2017
Derivative Instruments, Gain (Loss) [Line Items]        
Net gain (loss) on derivative instruments $ (1,548)   $ 15,336 $ 5,138
Predecessor        
Derivative Instruments, Gain (Loss) [Line Items]        
Net gain (loss) on derivative instruments   $ (6,838)