Long-Term Debt (Details) $ in Thousands					2 Months Ended	3 Months Ended	6 Months Ended	12 Months Ended
		Jan. 01, 2017	Dec. 31, 2015 USD ($)	Dec. 01, 2015 USD ($)	Feb. 29, 2016 USD ($)	Dec. 31, 2016	Jun. 30, 2016	Dec. 31, 2016	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Nov. 02, 2015 USD ($) Banks	May. 01, 2015 USD ($)	Oct. 03, 2012 USD ($)	Nov. 30, 2011 USD ($)	Nov. 25, 2009 USD ($)	Jun. 01, 2007 USD ($)
Bankruptcy Proceedings [Abstract]
Plan of Reogranization, percentage of common stock lenders to receive net of backstop fee			88.50%						88.50%
Bank Borrowings
Liabilities subject to compromise, senior notes			$ 905,629						$ 905,629
Long-Term Debt, excluding current maturities			0						0	$ 1,074,534
Total Debt			324,900						324,900
Number of syndicated banks | Banks												11
Interest expense including commitment fees and amortization of debt issuance costs relating to the credit facility									75,870	73,207	$ 69,382
Capitalized interest on our unproved properties									4,900	5,000	7,200
Debtor-in-Possession Financing [Abstract]
Debtor-in-Possession Financing, Amount Currently Available			30,000						30,000
Debtor-in-Possession Financing, Unused Borrowings			$ 45,000						$ 45,000
DIP Financing, percentage of applicable margin with LIBOR									12.00%
DIP Financing, percentage of applicable margin with ABR									11.00%
Debtor-in-Possession Financing, Fee on Unused Borrowings			3.00%						3.00%
Plan of Reorganization, backstop fee			7.50%						7.50%
DIP Financing, fee paid on drawdowns against DIP facility			5.00%						5.00%
DIP Financing, net proceeds after drawdown fee			95.00%						95.00%
Senior Notes [Member]
Bank Borrowings
Reorganization Items, write-off of debt issuance costs and debt discounts									$ 8,662
Interest expense including commitment fees and amortization of debt issuance costs relating to the credit facility									70,800	70,700	70,600
Line of Credit [Member]
Bank Borrowings
Long-Term Debt, excluding current maturities										197,300
Revolving credit facility debt issuance costs			$ 3,300
Line of Credit, current borrowing base												$ 330,000	$ 375,000
Line of Credit, current commitment amount												$ 330,000	$ 375,000
Long-term Debt, Current Maturities			324,900						$ 324,900	0
Percentage of applicable margin with federal fund rate									0.50%
Percentage of applicable margin with LIBOR									1.00%
Interest expense including commitment fees and amortization of debt issuance costs relating to the credit facility									$ 9,400	7,500	6,000
Commitment fees included in interest expense, net									500	800	$ 1,100
Maximum level of cash dividends in any fiscal year			15,000						15,000
Aggregate limitation on purchases of stock			50,000						$ 50,000
Line of Credit, Required Security Interest on Oil and Gas Properties									95.00%
Line of Credit [Member] | Minimum [Member]
Bank Borrowings
Lead bank's prime rate									3.25%
Line of Credit Facility, Commitment Fee Percentage									0.375%
Line of Credit [Member] | Minimum [Member] | Alternative Base Interest Rate [Member]
Bank Borrowings
Debt Instrument escalating basis spread on base rate									100
Line of Credit [Member] | Minimum [Member] | Eurodollar Interest Rate [Member]
Bank Borrowings
Debt instrument escalating rates for eurodollar rate loans									200
Line of Credit [Member] | Maximum [Member]
Bank Borrowings
Lead bank's prime rate									3.50%
Line of Credit Facility, Commitment Fee Percentage									0.50%
Line of Credit [Member] | Maximum [Member] | Alternative Base Interest Rate [Member]
Bank Borrowings
Debt Instrument escalating basis spread on base rate									200
Line of Credit [Member] | Maximum [Member] | Eurodollar Interest Rate [Member]
Bank Borrowings
Debt instrument escalating rates for eurodollar rate loans									300
Senior Notes Due 2017 [Member] | Senior Notes [Member]
Bank Borrowings
Liabilities subject to compromise, senior notes			250,000						$ 250,000
Long-Term Debt, excluding current maturities			0						0	250,000							$ 250,000
Stated rate of senior notes																	7.125%
Reorganization Items, write-off of debt issuance costs and debt discounts									800
Missed interest payment on 2017 senior notes				$ 8,900
Senior Notes
Percentage at which senior notes are issued, of par value																	100.00%
Senior Notes Due 2020 [Member] | Senior Notes [Member]
Bank Borrowings
Liabilities subject to compromise, senior notes	[1]		225,000						225,000
Long-Term Debt, excluding current maturities			0						0	222,775
Stated rate of senior notes																8.875%
Reorganization Items, write-off of debt issuance costs and debt discounts									2,600
Senior Notes
Senior notes, issued																$ 225,000
Original unamortized issuance discount on senior notes																$ 3,600
Percentage at which senior notes are issued, of par value																98.389%
Effective interest rate on senior notes including discount																9.125%
Senior Notes Due 2022 [Member] | Senior Notes [Member]
Bank Borrowings
Liabilities subject to compromise, senior notes	[1]		400,000						400,000
Long-Term Debt, excluding current maturities			$ 0						0	$ 404,459
Stated rate of senior notes														7.875%
Reorganization Items, write-off of debt issuance costs and debt discounts									5,300
Reorganization Items, write-off of debt premiums									3,961
Senior Notes
Senior notes, issued														$ 400,000	$ 250,000
Original unamortized issuance discount on senior notes															$ 2,100
Percentage at which senior notes are issued, of par value															99.156%
Effective interest rate on senior notes including discount															8.00%
Debt Discount on Senior Notes Due 2020 [Member] | Senior Notes [Member]
Bank Borrowings
Reorganization Items, write-off of debt issuance costs and debt discounts									$ 1,864
Additional Senior Notes Due 2022 [Member] | Senior Notes [Member]
Senior Notes
Senior notes, issued														$ 150,000
Percentage at which senior notes are issued, of par value														105.00%
Effective interest rate on senior notes including discount														6.993%
Subsequent Event [Member]
Debtor-in-Possession Financing [Abstract]
Debtor Reorganization Items, Debtor-in-Possession Facility Financing Costs					$ 900
Subsequent Event [Member] | Line of Credit [Member]
Bank Borrowings
Line of Credit, Working Capital Ratio Required		1.0						0.5
Line of Credit, Covenant, Interest Coverage Ratio, Required		2.0				1.3	1.15
Line of Credit, Covenant, Senior Secured Leverage Ratio, Minimum		2.5				3.0	3.5

[1] Amounts are shown net of any debt discount or premium