Long-Term Debt (Details) $ in Thousands					3 Months Ended		4 Months Ended	5 Months Ended	9 Months Ended
	Mar. 31, 2019	Sep. 30, 2016 USD ($)	Jun. 30, 2016	Apr. 22, 2016 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)	Apr. 22, 2016 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)	Dec. 31, 2015 USD ($)	Oct. 03, 2012 USD ($)	Nov. 25, 2009 USD ($)	Jun. 01, 2007
Debt Instrument [Line Items]
Document Period End Date									Sep. 30, 2016
Plan of Reogranization, percentage of common stock lenders to receive net of backstop fee				88.50%			88.50%
Debtor-in-Possession Financing
Debtor-in-Possession Financing, Amount Arranged				$ 75,000			$ 75,000
Senior Notes
Debt and Accrued interest				$ 905,629			$ 905,629
DIP Facility [Member]
Debt Instrument [Line Items]
Plan of Reogranization, percentage of common stock lenders to receive net of backstop fee				88.50%			88.50%
Debtor-in-Possession Financing
Debtor-in-Possession Financing, Amount Arranged				$ 75,000			$ 75,000
Debtor-in-Possession Financing, Fee on Unused Borrowings				3.00%			3.00%
Senior Notes [Member]
Bank Borrowings and New Credit Facility
Interest expense including amortization of debt issuance costs						$ 17,700				$ 53,000
Senior Notes [Member] | Senior Notes Due 2017 [Member]
Senior Notes
Debt and Accrued interest											$ 250,000
Senior notes, issued													$ 250,000
Debt instrument, interest rate, stated percentage														7.125%
Percentage at which senior notes are issued, of par value														100.00%
Senior Notes [Member] | Senior Notes Due 2020 [Member]
Senior Notes
Debt and Accrued interest											225,000
Senior notes, issued													$ 225,000
Debt instrument, interest rate, stated percentage													8.875%
Percentage at which senior notes are issued, of par value													98.389%
Effective Interest Rate On Senior Notes Including Discount													9.125%
Senior Notes [Member] | Senior Notes Due 2022 [Member]
Senior Notes
Debt and Accrued interest											400,000
Senior notes, issued												$ 400,000
Debt instrument, interest rate, stated percentage												7.875%
Line of Credit [Member]
Bank Borrowings and New Credit Facility
Percentage of applicable margin with federal fund rate							0.50%
Percentage of applicable margin with LIBOR							1.00%
Commitment fee basis points for the credit facility							0.50%
Line of Credit [Member] | Minimum [Member] | Alternative Base Interest Rate [Member]
Bank Borrowings and New Credit Facility
Debt instrument escalating basis spread on base rate							100
Line of Credit [Member] | Minimum [Member] | Eurodollar Interest Rate [Member]
Bank Borrowings and New Credit Facility
Debt Instrument Escalating Rates for Eurodollar Rate Loans							200
Line of Credit [Member] | Maximum [Member] | Alternative Base Interest Rate [Member]
Bank Borrowings and New Credit Facility
Debt instrument escalating basis spread on base rate							200
Line of Credit [Member] | Maximum [Member] | Eurodollar Interest Rate [Member]
Bank Borrowings and New Credit Facility
Debt Instrument Escalating Rates for Eurodollar Rate Loans							300
Line of Credit [Member] | New Credit Facility [Member]
Bank Borrowings and New Credit Facility
Line of Credit Facility, Maximum Borrowing Capacity				$ 500,000			$ 500,000
Line of Credit Facility, Current Borrowing Capacity				$ 320,000			320,000
Line of Credit, Required Security Interest on Oil and Gas Properties				95.00%
Line of Credit Facility, Non-Conforming Borrowing Base				$ 70,000
Line of Credit Facility, Conforming Borrowing Base				250,000
Line of Credit Facility, Non-Conforming Borrowing Base, Borrowings Outstanding		$ 4,000			$ 4,000			$ 4,000	$ 4,000
Line of Credit Facility, Conforming Borrowing Base, Borrowings Outstanding		$ 250,000			$ 250,000			$ 250,000	$ 250,000
Debt, Weighted Average Interest Rate		7.52557%			7.52557%			7.52557%	7.52557%
Line of Credit, Covenant, Debt to EBITDA Ratio, Minimum		6.5
Line of Credit, Covenant, Current Ratio, Minimum			1.0
Line of Credit, Covenant, Liquidity Requirement, Minimum				$ 10,000
Line of Credit [Member] | New Credit Facility [Member] | Minimum [Member] | Alternative Base Interest Rate [Member]
Bank Borrowings and New Credit Facility
Debt Instrument Escalating Basis Spread on Base Rate During Non-Conforming Period				500
Debt Instrument Escalating Basis Spread on Base Rate After Non-Conforming Period				200
Line of Credit [Member] | New Credit Facility [Member] | Minimum [Member] | Eurodollar Interest Rate [Member]
Bank Borrowings and New Credit Facility
Debt Instrument Escalating Rates for Eurodollar Rate Loans During Non-Conforming Period				600
Debt Instrument Escalating Rates for Eurodollar Rate Loans After Non-Conforming Period				300
Line of Credit [Member] | New Credit Facility [Member] | Maximum [Member] | Alternative Base Interest Rate [Member]
Bank Borrowings and New Credit Facility
Debt Instrument Escalating Basis Spread on Base Rate During Non-Conforming Period				600
Debt Instrument Escalating Basis Spread on Base Rate After Non-Conforming Period				300
Line of Credit [Member] | New Credit Facility [Member] | Maximum [Member] | Eurodollar Interest Rate [Member]
Bank Borrowings and New Credit Facility
Debt Instrument Escalating Rates for Eurodollar Rate Loans During Non-Conforming Period				700
Debt Instrument Escalating Rates for Eurodollar Rate Loans After Non-Conforming Period				400
Predecessor [Member]
Debt Instrument [Line Items]
Long-term Debt, Excluding Current Maturities											0
Long-term Debt											324,900
Bank Borrowings and New Credit Facility
Long-term Debt, Current Maturities											324,900
Interest expense including amortization of debt issuance costs						19,438	13,347			56,407
Predecessor [Member] | DIP Facility [Member]
Bank Borrowings and New Credit Facility
Interest expense including amortization of debt issuance costs							6,400
Debtor-in-Possession Financing
Debtor-in-Possession Financing, Commitment Fees Paid							900
Predecessor [Member] | Senior Notes Due 2017 [Member]
Debt Instrument [Line Items]
Long-term Debt, Excluding Current Maturities											0
Predecessor [Member] | Senior Notes Due 2020 [Member]
Debt Instrument [Line Items]
Long-term Debt, Excluding Current Maturities											0
Predecessor [Member] | Senior Notes Due 2022 [Member]
Debt Instrument [Line Items]
Long-term Debt, Excluding Current Maturities											0
Predecessor [Member] | Bank Borrowings [Member]
Bank Borrowings and New Credit Facility
Long-term Debt, Current Maturities											$ 324,900
Predecessor [Member] | Senior Notes [Member]
Bank Borrowings and New Credit Facility
Interest expense including amortization of debt issuance costs							0
Senior Notes
Contractual Interest Expense on Prepetition Liabilities Not Recognized in Statement of Operations							21,600
Predecessor [Member] | Line of Credit [Member]
Bank Borrowings and New Credit Facility
Interest expense including amortization of debt issuance costs						2,300	6,800			6,300
Commitment fees included in interest expense, net						100	0			500
Capitalized interest on our unproved properties						$ 1,200	$ 0			$ 3,600
Successor [Member]
Debt Instrument [Line Items]
Long-term Debt, Excluding Current Maturities		$ 254,000			$ 254,000			$ 254,000	$ 254,000
Long-term Debt		254,000			254,000			254,000	254,000
Bank Borrowings and New Credit Facility
Long-term Debt, Current Maturities		0			0			0	0
Interest expense including amortization of debt issuance costs					5,880			10,137
Successor [Member] | Senior Notes Due 2017 [Member]
Debt Instrument [Line Items]
Long-term Debt, Excluding Current Maturities		0			0			0	0
Successor [Member] | Senior Notes Due 2020 [Member]
Debt Instrument [Line Items]
Long-term Debt, Excluding Current Maturities		0			0			0	0
Successor [Member] | Senior Notes Due 2022 [Member]
Debt Instrument [Line Items]
Long-term Debt, Excluding Current Maturities		0			0			0	0
Successor [Member] | Bank Borrowings [Member]
Debt Instrument [Line Items]
Long-term Debt		$ 254,000			254,000			254,000	$ 254,000
Successor [Member] | Line of Credit [Member]
Bank Borrowings and New Credit Facility
Capitalized interest on our unproved properties					300			300
Successor [Member] | Line of Credit [Member] | New Credit Facility [Member]
Bank Borrowings and New Credit Facility
Interest expense including amortization of debt issuance costs					6,100			10,400
Commitment fees included in interest expense, net					$ 100			$ 100
Subsequent Event [Member] | Line of Credit [Member] | New Credit Facility [Member]
Bank Borrowings and New Credit Facility
Line of Credit, Covenant, Debt to EBITDA Ratio, Minimum	3.5