Fresh Start Accounting Fresh Start Accounting Narrative (Details) $ / shares in Units, $ in Thousands	Apr. 22, 2016 USD ($) $ / shares shares
Fresh-Start Adjustment [Line Items]
Enterprise Value	$ 473,660
Discount Rate on Risk Adjusted After Tax Cash Flows	0.12
Fair Value of Proved Reserves	$ 509,400
Fair Value of Probable Reserves	$ 45,500
Number of Series of Warrants Issued	2
Class of Warrant or Right, Percentage of Total Equity	15.00%
Class of Warrant or Right, Number of Securities Called by Warrants or Rights | shares	4,300,000.0
Class of Warrant or Right, Fair Value Disclosure, Per Share | $ / shares	$ 3.49
Fair Value Assumptions, Expected Dividend Rate	0.00%
Debtor-in-Possession Financing, Amount Arranged	$ 75,000
Value of Equity Issuance for DIP Credit Agreement	$ 142,300
Stock Issued During Period, Shares, New Issues | shares	10,000,000.0
Plan or Reorganization, warrants existing equity holders	30.00%
Stock and Warrants Issued During Period, Value, Preferred Stock and Warrants	$ 15,000
Reorganization Adjustments [Member]
Fresh-Start Adjustment [Line Items]
Debtor Reorganization Items, Net Gain (Loss) on Rejection of Leases and Other Executory Contracts	600
Debtor Reorganization Items, Discharge of Claims and Liabilities	5,200
Minimum [Member]
Fresh-Start Adjustment [Line Items]
Enterprise Value	460,000
Maximum [Member]
Fresh-Start Adjustment [Line Items]
Enterprise Value	800,000
New Credit Facility [Member]
Fresh-Start Adjustment [Line Items]
Proceeds from Issuance of Debt	253,000
Payments of Debt Issuance Costs	7,000
New Credit Facility [Member] | Reorganization Adjustments [Member]
Fresh-Start Adjustment [Line Items]
Proceeds from Issuance of Debt	253,000
Payments of Debt Issuance Costs	6,482
Debt Issuance Costs, Net	7,000
Prior First Lean Credit Facility [Member]
Fresh-Start Adjustment [Line Items]
Repayments of Debt	$ 289,500
2019 Warrants [Member]
Fresh-Start Adjustment [Line Items]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights | shares	2,142,857
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares	$ 80.00
Class of Warrant or Right, Fair Value Disclosure, Per Share | $ / shares	3.26
Class of Warrant or Right, Strike Price | $ / shares	$ 80
Fair Value Assumptions, Expected Volatility Rate	70.00%
Fair Value Assumptions, Risk Free Interest Rate	1.01%
Fair Value Assumptions, Expected Term	3 years
2020 Warrants [Member]
Fresh-Start Adjustment [Line Items]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights | shares	2,142,857
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares	$ 86.18
Class of Warrant or Right, Fair Value Disclosure, Per Share | $ / shares	3.73
Class of Warrant or Right, Strike Price | $ / shares	$ 86.18
Fair Value Assumptions, Expected Volatility Rate	65.00%
Fair Value Assumptions, Risk Free Interest Rate	1.19%
Fair Value Assumptions, Expected Term	4 years
Accounts Payable and Accrued Liabilities [Member] | New Credit Facility [Member] | Reorganization Adjustments [Member]
Fresh-Start Adjustment [Line Items]
Debt Issuance Costs, Net	$ 500
Former Holders of Senior Notes [Member]
Fresh-Start Adjustment [Line Items]
Stockholders' Equity Attributable to Parent, Excluding Warrants, Per Share | $ / shares	$ 21.44
Holders of General Unsecured and Retiree Committee Unsecured Claims [Member]
Fresh-Start Adjustment [Line Items]
Stock Issued During Period, Shares, New Issues | shares	8,850,000.00
Backstop Lenders [Member]
Fresh-Start Adjustment [Line Items]
Stock Issued During Period, Shares, New Issues | shares	750,000.00
Former Shareholders [Member]
Fresh-Start Adjustment [Line Items]
Stock Issued During Period, Shares, New Issues | shares	400,000.0