Supplemental disclosures to the consolidated statements of cash flows (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended	12 Months Ended
	Mar. 21, 2017	Sep. 30, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net cash provided by operating activities included:
Cash payments for interest			$ 17,195
Interest capitalized			(2,142)
Cash payments for interest, net of amounts capitalized			15,053
Cash payments for income taxes			150
Cash payments for reorganization items			18,006
Non-cash investing activities included:
Asset retirement obligation additions and revisions			6,746
Change in accrued oil and gas capital expenditures			$ 9,534
Predecessor
Net cash provided by operating activities included:
Cash payments for interest	$ 4,105			$ 25,764	$ 116,379
Interest capitalized	(248)			(2,139)	(9,670)
Cash payments for interest, net of amounts capitalized	3,857			23,625	106,709
Cash payments for income taxes				250	640
Cash payments for reorganization items	11,405			10,670
Non-cash financing activities included:
Repayment of Prior Credit Facility with proceeds from early termination of derivative contracts (See Note 9)		$ 103,560		103,560
Non-cash investing activities included:
Asset retirement obligation additions and revisions	716			22,282	4,000
Change in accrued oil and gas capital expenditures	$ 5,387			$ (19,725)	$ (105,312)