Fair Value (Details) $ in Thousands	3 Months Ended
Mar. 31, 2021 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2020 USD ($)
Assets
Derivative Assets, Fair Value, Gross Asset	$ 34,426		$ 54,353
Liabilities
Derivative Liability, Fair Value, Gross Liability	(439,397)		$ (222,520)
Oil and Gas Property [Abstract]
Property, Plant, and Equipment, Fair Value Disclosure	0
Impairment of proved oil and gas properties and related support equipment	0	$ 956,700
Abandonment and impairment of unproved properties	$ 8,800	$ 33,100
1.50% Senior Secured Convertible Notes Due 2021 [Member]
Debt Instrument, Fair Value Disclosure [Abstract]
Senior Notes, interest rate, stated percentage	1.50%		1.50%
Senior Notes, Principal amount	$ 65,485		$ 65,485
Long-term Debt, Fair Value	$ 63,864		$ 61,449
10.0% Senior Secured Notes due 2025 [Member]
Debt Instrument, Fair Value Disclosure [Abstract]
Senior Notes, interest rate, stated percentage	10.00%		10.00%
Senior Notes, Principal amount	$ 446,675		$ 446,675
Long-term Debt, Fair Value	$ 502,858		$ 482,887
6.125% Senior Unsecured Notes due 2022 [Member]
Debt Instrument, Fair Value Disclosure [Abstract]
Senior Notes, interest rate, stated percentage	6.125%		6.125%
Senior Notes, Principal amount	$ 212,403		$ 212,403
Long-term Debt, Fair Value	$ 209,633		$ 205,379
5.0% Senior Unsecured Notes due 2024 [Member]
Debt Instrument, Fair Value Disclosure [Abstract]
Senior Notes, interest rate, stated percentage	5.00%		5.00%
Senior Notes, Principal amount	$ 277,034		$ 277,034
Long-term Debt, Fair Value	$ 261,936		$ 240,072
5.625% Senior Unsecured Notes due 2025 [Member]
Debt Instrument, Fair Value Disclosure [Abstract]
Senior Notes, interest rate, stated percentage	5.625%		5.625%
Senior Notes, Principal amount	$ 349,118		$ 349,118
Long-term Debt, Fair Value	$ 323,007		$ 289,401
6.75% Senior Unsecured Notes due 2026 [Member]
Debt Instrument, Fair Value Disclosure [Abstract]
Senior Notes, interest rate, stated percentage	6.75%		6.75%
Senior Notes, Principal amount	$ 419,235		$ 419,235
Long-term Debt, Fair Value	$ 387,373		$ 342,385
6.625% Senior Unsecured Notes due 2027 [Member]
Debt Instrument, Fair Value Disclosure [Abstract]
Senior Notes, interest rate, stated percentage	6.625%		6.625%
Senior Notes, Principal amount	$ 416,791		$ 416,791
Long-term Debt, Fair Value	384,323		331,220
Fair Value, Nonrecurring [Member] \| Measurement Input, Discount Rate [Member] \| Oil and Gas Properties
Oil and Gas Property [Abstract]
Fair Value Assumptions, Measurement Input		0.11
Not Designated as Hedging Instrument [Member] \| Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member]
Assets
Derivative Assets, Fair Value, Gross Asset	0		0
Liabilities
Derivative Liability, Fair Value, Gross Liability	0		0
Not Designated as Hedging Instrument [Member] \| Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member]
Assets
Derivative Assets, Fair Value, Gross Asset	34,426		54,353
Liabilities
Derivative Liability, Fair Value, Gross Liability	439,397		222,520
Not Designated as Hedging Instrument [Member] \| Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member]
Assets
Derivative Assets, Fair Value, Gross Asset	0		0
Liabilities
Derivative Liability, Fair Value, Gross Liability	$ 0		$ 0

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The impairment expense recorded to reduce the value of proved oil and gas assets.

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Accumulated expirations or loss on unproved oil and gas properties.

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Face (par) amount of debt instrument at time of issuance.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

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Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

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The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

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Fair value portion of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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