Debt (Details) $ in Thousands				1 Months Ended	2 Months Ended	3 Months Ended	4 Months Ended	6 Months Ended
	Mar. 31, 2019	Jun. 30, 2016 USD ($)	Apr. 22, 2016 USD ($)	Apr. 22, 2016 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2015 USD ($)	Apr. 22, 2016 USD ($)	Jun. 30, 2015 USD ($)	Dec. 31, 2015 USD ($)	Oct. 03, 2012 USD ($)	Nov. 25, 2009 USD ($)	Jun. 01, 2007
Debtor-in-Possession Financing
Plan of Reogranization, percentage of common stock lenders to receive net of backstop fee			88.50%	88.50%			88.50%
Debtor-in-Possession Financing, Amount Arranged			$ 75,000	$ 75,000			$ 75,000
Plan of Reorganization, backstop fee			7.50%	7.50%			7.50%
Bank Borrowings and New Credit Facility
Debt and Accrued interest			$ 905,629	$ 905,629			$ 905,629
DIP Facility [Member]
Debtor-in-Possession Financing
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%			3.00%
Plan of Reorganization, backstop fee			7.50%	7.50%			7.50%
DIP Financing, fee paid on drawdowns against DIP facility			5.00%	5.00%			5.00%
DIP Financing, net proceeds after drawdown fee			95.00%	95.00%			95.00%
Senior Notes [Member]
Bank Borrowings and New Credit Facility
Interest expense including amortization of debt issuance costs				$ 0		$ 17,700	$ 0	$ 35,400
Senior Notes [Member] | Senior Notes Due 2022 [Member]
Bank Borrowings and New Credit Facility
Debt and Accrued interest									$ 400,000
Senior Notes
Senior notes, issued										$ 400,000
Debt instrument, interest rate, stated percentage										7.875%
Senior Notes [Member] | Senior Notes Due 2020 [Member]
Bank Borrowings and New Credit Facility
Debt and Accrued interest									225,000
Senior Notes
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 2017 [Member]
Bank Borrowings and New Credit Facility
Debt and Accrued interest									250,000
Senior Notes
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%
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			$ 500,000
Line of Credit Facility, Current Borrowing Capacity			$ 320,000	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
Line of Credit Facility, Conforming Borrowing Base, Borrowings Outstanding		$ 250,000			250,000
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									324,900
Long-term Debt, Excluding Current Maturities									0
Bank Borrowings and New Credit Facility
Long-term Debt, Current Maturities									324,900
Interest expense including amortization of debt issuance costs				5,281		18,741	13,347	36,969
Contractual Interest Expense on Prepetition Liabilities Not Recognized in Statement of Operations				4,200			21,600
Predecessor [Member] | DIP Facility [Member]
Debtor-in-Possession Financing
Debtor-in-Possession Financing, Commitment Fees Paid							900
Bank Borrowings and New Credit Facility
Interest expense including amortization of debt issuance costs				4,500			6,400
Predecessor [Member] | Senior Notes Due 2022 [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 2017 [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] | Line of Credit [Member]
Bank Borrowings and New Credit Facility
Interest expense including amortization of debt issuance costs				700		2,200	6,800	4,000
Commitment fees included in interest expense, net				$ 0		100	0	400
Capitalized interest on our unproved properties						$ 1,200	$ 0	$ 2,400
Successor [Member]
Debt Instrument [Line Items]
Long-term Debt		$ 254,000			254,000
Long-term Debt, Excluding Current Maturities		254,000			254,000
Bank Borrowings and New Credit Facility
Long-term Debt, Current Maturities		0			0
Interest expense including amortization of debt issuance costs					4,257
Successor [Member] | Senior Notes Due 2022 [Member]
Debt Instrument [Line Items]
Long-term Debt, Excluding Current Maturities		0			0
Successor [Member] | Senior Notes Due 2020 [Member]
Debt Instrument [Line Items]
Long-term Debt, Excluding Current Maturities		0			0
Successor [Member] | Senior Notes Due 2017 [Member]
Debt Instrument [Line Items]
Long-term Debt, Excluding Current Maturities		0			0
Successor [Member] | New Credit Facility [Member]
Bank Borrowings and New Credit Facility
Interest expense including amortization of debt issuance costs					4,300
Commitment fees included in interest expense, net					100
Successor [Member] | Bank Borrowings [Member]
Debt Instrument [Line Items]
Long-term Debt		$ 254,000			254,000
Successor [Member] | Line of Credit [Member]
Bank Borrowings and New Credit Facility
Capitalized interest on our unproved properties					$ 0
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