Consolidated income tax provision (benefit) (Details) - USD ($) $ in Thousands	4 Months Ended	8 Months Ended	12 Months Ended
	Apr. 22, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Predecessor [Member]
Summary of consolidated income tax provision (benefit)
Current income taxes	$ 0		$ (410)	$ 314
Deferred income taxes	0		(80,133)	(150,357)
Income tax provision (benefit)	$ 0		$ (80,543)	$ (150,043)
Successor [Member]
Summary of consolidated income tax provision (benefit)
Current income taxes		$ 0
Deferred income taxes		0
Income tax provision (benefit)		$ 0