Covenant compliance ratio related to EBITDAX to interest expense.

No definition available.

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Debt Instrument, Covenant Terms, Future Earnings Before Income Tax Depreciation Depletion Amortization and Exploration Expenses, Ratio

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Debt Instrument, Covenant Terms, Minimum Acquisition Payment Limit

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Debt Instrument, Covenant Terms, Minimum Disposition of Property Limit

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Debt Instrument, Disposition Costs Maximum Expenses Allowed

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Debt Instrument, Number of Banks Added to Syndicate

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Line of Credit Facility, Elected Commitment

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Line of Credit Facility, Required Minimum Down Payment, Percent

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Percentage points added to the reference rate to compute the variable rate on the debt instrument.

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Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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

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The average effective interest rate during the reporting period.

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Incremental percentage increase (decrease) in the stated rate on a debt instrument.

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No definition available.

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

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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Amount of interest capitalized during the period.

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The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility.

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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The cash inflow from a borrowing with the highest claim on the assets of the entity in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle, if longer).

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Long-Term Debt - Additional Information (Details)						1 Months Ended	12 Months Ended
Long-Term Debt - Additional Information (Details)	May 21, 2018 USD ($)	Nov. 21, 2017	May 04, 2017 USD ($) bank	Dec. 21, 2016 USD ($)	Oct. 14, 2016 USD ($)	Jan. 31, 2016	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Nov. 28, 2018 USD ($)	Oct. 11, 2017 USD ($)	May 03, 2017 USD ($)	Mar. 29, 2017 USD ($)	Jun. 04, 2015 USD ($)	Apr. 21, 2015 USD ($)
Debt Instrument [Line Items]
Long-tern debt							$ 2,118,149,000
Deferred finance costs							30,733,000	$ 34,781,000
Capitalized interest costs							4,470,000	9,470,000	$ 9,148,000
Revolving credit agreement
Debt Instrument [Line Items]
Debt issued								0
Construction loans
Debt Instrument [Line Items]
Debt issued							23,149,000	23,724,000
Oil and gas properties
Debt Instrument [Line Items]
Capitalized interest costs							$ 4,500,000	$ 9,500,000
Nova Scotia, Amegy, KeyBank \| Revolving credit agreement
Debt Instrument [Line Items]
Weight average interest rate							4.23%
Nova Scotia, Amegy, KeyBank \| Base Rate \| Minimum
Debt Instrument [Line Items]
Stated interest rate							0.25%
Nova Scotia, Amegy, KeyBank \| Base Rate \| Maximum
Debt Instrument [Line Items]
Stated interest rate							1.25%
Nova Scotia, Amegy, KeyBank \| Federal Funds Rate
Debt Instrument [Line Items]
Basis spread on variable rate							0.50%
Nova Scotia, Amegy, KeyBank \| Eurodollar
Debt Instrument [Line Items]
Basis spread on variable rate							1.00%
Nova Scotia, Amegy, KeyBank \| Eurodollar \| Minimum
Debt Instrument [Line Items]
Stated interest rate							1.25%
Nova Scotia, Amegy, KeyBank \| Eurodollar \| Maximum
Debt Instrument [Line Items]
Stated interest rate							2.25%
InterBank \| Revolving credit agreement \| Construction loans
Debt Instrument [Line Items]
Maximum borrowing capacity														$ 24,500,000
Stated interest rate														4.50%
InterBank \| Letter of credit \| Construction loans
Debt Instrument [Line Items]
Required minimum down payment percentage						30.00%
Deferred finance costs							$ 100,000
Debt issued							$ 23,100,000
Amended and Restated Credit Agreement \| Maximum
Debt Instrument [Line Items]
Debt covenant ratio for future EBITDAX							4.00
Amended and Restated Credit Agreement \| Revolving credit agreement
Debt Instrument [Line Items]
Debt covenant ratio for EBITDAX							3.00
Amended and Restated Credit Agreement \| Nova Scotia, Amegy, KeyBank \| Revolving credit agreement
Debt Instrument [Line Items]
Maximum borrowing capacity							$ 1,500,000,000
Amended and Restated Credit Agreement \| Nova Scotia, Amegy, KeyBank \| Revolving credit agreement
Debt Instrument [Line Items]
Borrowing base	$ 1,400,000,000.0		$ 1,000,000,000.0				1,200,000,000.0					$ 700,000,000.0
Minimum acquisition payment limit													$ 50,000,000.0
Minimum disposition of property limit													$ 50,000,000.0
Number of banks added to syndicate \| bank			5
Increase (decrease) in interest rate	(0.25%)	0.50%
Debt issued							45,000,000
Amended and Restated Credit Agreement \| Nova Scotia, Amegy, KeyBank \| Letter of credit
Debt Instrument [Line Items]
Long-term line of credit outstanding							316,600,000
Line of credit facility, elected commitment	$ 1,000,000,000.0						1,000,000,000.0			$ 1,000,000,000.0
Future borrowings available							638,400,000
Disposition costs, maximum expenses allowed							$ 3,000,000.0
7.75% Senior Notes Due 2020 \| Senior notes
Debt Instrument [Line Items]
Stated interest rate							7.75%	7.75%
6.625% Senior Notes Due 2023 \| Senior notes
Debt Instrument [Line Items]
Stated interest rate							6.625%	6.625%							6.625%
Long-tern debt															$ 343,600,000
Aggregate principal amount															$ 350,000,000.0
Deferred finance costs							$ 4,400,000
Debt issued							$ 350,000,000	$ 350,000,000
6.000% Senior Notes Due 2024 \| Senior notes
Debt Instrument [Line Items]
Stated interest rate					6.00%		6.00%	6.00%
Aggregate principal amount					$ 650,000,000.0
Proceeds from issuance of Senior notes					$ 638,900,000
Deferred finance costs							$ 8,700,000
Debt issued							$ 650,000,000	$ 650,000,000
6.375% Senior Notes Due 2025 \| Senior notes
Debt Instrument [Line Items]
Stated interest rate				6.375%			6.375%	6.375%
Aggregate principal amount				$ 600,000,000
Proceeds from issuance of Senior notes				$ 584,700,000
Deferred finance costs							$ 12,500,000
Debt issued							$ 600,000,000	$ 600,000,000
6.375% Senior Notes Due 2026 \| Senior notes
Debt Instrument [Line Items]
Stated interest rate							6.375%	6.375%			6.375%
Long-tern debt											$ 444,100,000
Aggregate principal amount											$ 450,000,000
Deferred finance costs							$ 5,000,000
Debt issued							$ 450,000,000	$ 450,000,000