FRESH START ACCOUNTING - Additional Information (Details) - USD ($)				1 Months Ended		2 Months Ended	3 Months Ended
	Mar. 01, 2017	Feb. 28, 2017	Feb. 27, 2017	Mar. 31, 2017	Oct. 31, 2016	Feb. 28, 2017	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2015
Fresh-Start Adjustment [Line Items]
Accumulated deficit		$ 555,066,000		$ 295,544,000		$ 555,066,000
Enterprise value		$ 419,720,000				419,720,000
Annual escalation adjustment rate		2.00%
Expected period for development to begin		5 years
Proved reserves		$ 380,800,000				380,800,000
Probable and possible reserves		16,800,000				16,800,000
Unevaluated properties reserves		80,200,000				80,200,000
Fair value of asset retirement obligations		$ 290,067,000				290,067,000
Credit-adjusted risk free rate		12.00%
Repayment of outstanding borrowings under Pre-Emergence Credit Agreement		$ 341,500,000		$ 0
New shares issued in reorganization (in shares)	20,000,000.0	20,000,000		0
Emergence and success fees		$ 15,180,000
Professional fees		2,600,000
Predecessor Company's Common Stockholders
Fresh-Start Adjustment [Line Items]
Warrants issued in reorganization (in shares)				3,500,000.0
Exercise price of warrants or rights (in usd per share)				$ 42.04
Exercise period for warrants				4 years
Senior Notes | 7 1⁄2% Senior Notes due 2022
Fresh-Start Adjustment [Line Items]
Aggregate principal amount of senior subordinated notes	$ 225,000,000.0
Predecessor
Fresh-Start Adjustment [Line Items]
Accumulated deficit		(3,610,000)				(3,610,000)		$ (637,282,000)	$ (39,789,000)
Repayment of outstanding borrowings under Pre-Emergence Credit Agreement						$ 341,500,000	$ 20,000,000
New shares issued in reorganization (in shares)						47,390	50,131
Emergence and success fees						$ (10,600,000)
Professional fees						9,100,000
Appalachia Properties | Disposal Group, Disposed of by Sale
Fresh-Start Adjustment [Line Items]
Indemnity escrow release			$ 10,000,000
Revaluation of Assets
Fresh-Start Adjustment [Line Items]
Write off of unamortized debt issuance costs		2,577,000
Revaluation of Assets | Tug Hill, Inc
Fresh-Start Adjustment [Line Items]
Net reimbursement in connection with the sale of asset		699,000				699,000
Loss on contract termination					$ 1,750,000
Revaluation of Liabilities | Senior Notes | 7 1⁄2% Senior Notes due 2022
Fresh-Start Adjustment [Line Items]
Aggregate principal amount of senior subordinated notes		225,000,000				225,000,000
Revaluation of Liabilities | Predecessor
Fresh-Start Adjustment [Line Items]
Repayment of outstanding borrowings under Pre-Emergence Credit Agreement						341,500,000
Revaluation of Liabilities | Leasing Arrangement
Fresh-Start Adjustment [Line Items]
Loss on contract termination		395,000
Revaluation of Liabilities | Appalachia Properties | Disposal Group, Disposed of by Sale
Fresh-Start Adjustment [Line Items]
Settlement of a property tax accrual		2,598,000				$ 2,598,000
Revaluation of Liabilities | Deferred Bonus | 2016 Incentive Plan
Fresh-Start Adjustment [Line Items]
Deferred compensation arrangement compensation expense		$ 2,008,000
Exchange of Stock for Stock
Fresh-Start Adjustment [Line Items]
Estimated fair value of the warrants (in usd per share)		$ 4.43				$ 4.43
Exchange of Stock for Stock | Predecessor Company's Common Stockholders
Fresh-Start Adjustment [Line Items]
Warrants issued in reorganization (in shares)		3,500,000.0
Exercise price of warrants or rights (in usd per share)		$ 42.04				$ 42.04
Exercise period for warrants		4 years
Exchange of Stock for Stock | Senior Notes | 7 1⁄2% Senior Notes due 2022 | Predecessor Company's Noteholders
Fresh-Start Adjustment [Line Items]
New shares issued in reorganization (in shares)		1,000,000.0
Exchange of Stock for Stock | Convertible Debt | 1.75% Senior Notes due 2017 | Predecessor Company's Noteholders
Fresh-Start Adjustment [Line Items]
New shares issued in reorganization (in shares)		19,000,000.0
Income Approach Valuation Technique
Fresh-Start Adjustment [Line Items]
Discounted weighted average cost of capital rate		12.50%
Minimum
Fresh-Start Adjustment [Line Items]
Enterprise value		$ 300,000,000				$ 300,000,000
Maximum
Fresh-Start Adjustment [Line Items]
Enterprise value		450,000,000				450,000,000
Accumulated Deficit
Fresh-Start Adjustment [Line Items]
Accumulated deficit		0		$ (259,613,000)		0
Accumulated Deficit | Predecessor
Fresh-Start Adjustment [Line Items]
Accumulated deficit		$ (1,665,892,000)				$ (1,665,892,000)		$ (2,296,209,000)	$ (1,705,623,000)