FRESH START ACCOUNTING - Reorganization Adjustments (Details) - USD ($) $ in Thousands			1 Months Ended	3 Months Ended
	Feb. 28, 2017	Feb. 27, 2017	Mar. 31, 2017	Mar. 31, 2018
Fresh-Start Adjustment [Line Items]
Net consideration received for sale of Appalachia Properties	$ 512,472		$ 10,770	$ 320
Cash transferred to restricted account	75,547
Break-up fee to Tug Hill	10,800
Repayment of outstanding borrowings under Pre-Emergence Credit Agreement	341,500		$ 0	$ 0
Repayment of 2017 Convertible Notes and 2022 Notes	100,000
Other fees and expenses	20,230
Total uses	548,077
Net change in cash, cash equivalents and restricted cash	(35,605)
Restricted cash for certain cure amounts	500
Emergence and success fees	15,200
Professional fees	2,700
Payments to seismic providers	2,400
Amended Credit Agreement
Fresh-Start Adjustment [Line Items]
Cash transferred to restricted account	$ 75,000
Disposal Group, Disposed of by Sale | Appalachia Properties
Fresh-Start Adjustment [Line Items]
Net consideration received for sale of Appalachia Properties		$ 512,500
Net consideration received for sale of Appalachia Properties		522,500
Indemnity escrow release		$ 10,000