Derivative Activities - Schedule of Additional Information Related to Master Netting Arrangements with Derivative Counterparties (Detail) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Derivative [Line Items]
Gross Amounts of Recognized Assets	$ 50,004	$ 152,692
Gross Amounts Offset in the Balance Sheet	(29,678)	(15,138)
Net Amounts of Assets Presented in the Balance Sheet	20,326	137,554
Gross Amounts of Recognized (Liabilities)	(114,589)	(29,206)
Gross Amounts Offset in the Balance Sheet	29,678	15,138
Net Amounts of (Liabilities) Presented in the Balance Sheet	(84,911)	(14,068)
Swaps \| Contingent Consideration
Derivative [Line Items]
Gross Amounts of Recognized Assets	15,420
Gross Amounts Offset in the Balance Sheet	0
Net Amounts of Assets Presented in the Balance Sheet	15,420
Commodity \| Swaps \| Natural Gas
Derivative [Line Items]
Gross Amounts of Recognized Assets	10,083	134,364
Gross Amounts Offset in the Balance Sheet	(9,159)	(2,913)
Net Amounts of Assets Presented in the Balance Sheet	924	131,451
Gross Amounts of Recognized (Liabilities)	(33,359)	(1,657)
Gross Amounts Offset in the Balance Sheet	9,159	2,913
Net Amounts of (Liabilities) Presented in the Balance Sheet	(24,200)	1,256
Commodity \| Swaps \| Crude Oil
Derivative [Line Items]
Gross Amounts of Recognized Assets	14,065	3,893
Gross Amounts Offset in the Balance Sheet	(13,566)	(4,794)
Net Amounts of Assets Presented in the Balance Sheet	499	(901)
Gross Amounts of Recognized (Liabilities)	0	(4,814)
Gross Amounts Offset in the Balance Sheet	13,566	4,794
Net Amounts of (Liabilities) Presented in the Balance Sheet	13,566	(20)
Commodity \| Swaps \| NGLs (C3-Propane)
Derivative [Line Items]
Gross Amounts of Recognized Assets	101
Gross Amounts Offset in the Balance Sheet	0
Net Amounts of Assets Presented in the Balance Sheet	101
Commodity \| Swaps \| NGLs (NC4-Normal Butane)
Derivative [Line Items]
Gross Amounts of Recognized Assets	17
Gross Amounts Offset in the Balance Sheet	(17)
Net Amounts of Assets Presented in the Balance Sheet	0
Commodity \| Swaps \| NGLs (C5-Natural Gasoline)
Derivative [Line Items]
Gross Amounts of Recognized Assets	25	60
Gross Amounts Offset in the Balance Sheet	0	(127)
Net Amounts of Assets Presented in the Balance Sheet	25	(67)
Gross Amounts of Recognized (Liabilities)		(127)
Gross Amounts Offset in the Balance Sheet		127
Net Amounts of (Liabilities) Presented in the Balance Sheet		0
Commodity \| Swaps \| NGLs (C4- Butane)
Derivative [Line Items]
Gross Amounts of Recognized Assets		167
Gross Amounts Offset in the Balance Sheet		0
Net Amounts of Assets Presented in the Balance Sheet		167
Commodity \| Three Way Collars \| Natural Gas
Derivative [Line Items]
Gross Amounts of Recognized Assets	680
Gross Amounts Offset in the Balance Sheet	(680)
Net Amounts of Assets Presented in the Balance Sheet	0
Gross Amounts of Recognized (Liabilities)	(40,563)
Gross Amounts Offset in the Balance Sheet	680
Net Amounts of (Liabilities) Presented in the Balance Sheet	(39,883)
Commodity \| Basis Swaps \| Natural Gas
Derivative [Line Items]
Gross Amounts of Recognized Assets	6,620	10,766
Gross Amounts Offset in the Balance Sheet	(3,263)	(1,092)
Net Amounts of Assets Presented in the Balance Sheet	3,357	9,674
Gross Amounts of Recognized (Liabilities)	(1,220)	(1,371)
Gross Amounts Offset in the Balance Sheet	3,263	1,092
Net Amounts of (Liabilities) Presented in the Balance Sheet	2,043	(279)
Commodity \| Spread Swaps \| NGLs (C3-Propane)
Derivative [Line Items]
Gross Amounts of Recognized Assets	2,974	1,913
Gross Amounts Offset in the Balance Sheet	(2,974)	(1,913)
Net Amounts of Assets Presented in the Balance Sheet	0	0
Gross Amounts of Recognized (Liabilities)	(3,503)	(16,040)
Gross Amounts Offset in the Balance Sheet	2,974	1,913
Net Amounts of (Liabilities) Presented in the Balance Sheet	(529)	(14,127)
Commodity \| Swaptions \| Natural Gas
Derivative [Line Items]
Gross Amounts of Recognized Assets		0
Gross Amounts Offset in the Balance Sheet		(1,325)
Net Amounts of Assets Presented in the Balance Sheet		(1,325)
Gross Amounts of Recognized (Liabilities)	(20,368)	(2,594)
Gross Amounts Offset in the Balance Sheet	0	1,325
Net Amounts of (Liabilities) Presented in the Balance Sheet	(20,368)	(1,269)
Commodity \| Swaptions \| Crude Oil
Derivative [Line Items]
Gross Amounts of Recognized Assets		0
Gross Amounts Offset in the Balance Sheet		(1,597)
Net Amounts of Assets Presented in the Balance Sheet		(1,597)
Gross Amounts of Recognized (Liabilities)		(2,254)
Gross Amounts Offset in the Balance Sheet		1,597
Net Amounts of (Liabilities) Presented in the Balance Sheet		(657)
Commodity \| Collars \| Natural Gas
Derivative [Line Items]
Gross Amounts of Recognized (Liabilities)	(14,169)
Gross Amounts Offset in the Balance Sheet	0
Net Amounts of (Liabilities) Presented in the Balance Sheet	(14,169)
Commodity \| Calls \| Crude Oil
Derivative [Line Items]
Gross Amounts of Recognized Assets		0
Gross Amounts Offset in the Balance Sheet		(349)
Net Amounts of Assets Presented in the Balance Sheet		(349)
Gross Amounts of Recognized (Liabilities)		(349)
Gross Amounts Offset in the Balance Sheet		349
Net Amounts of (Liabilities) Presented in the Balance Sheet		0
Commodity \| Calls \| NGLs (NC4-Normal Butane)
Derivative [Line Items]
Gross Amounts of Recognized (Liabilities)	0
Gross Amounts Offset in the Balance Sheet	17
Net Amounts of (Liabilities) Presented in the Balance Sheet	17
Freight \| Swaps
Derivative [Line Items]
Gross Amounts of Recognized Assets	19	1,529
Gross Amounts Offset in the Balance Sheet	(19)	(1,028)
Net Amounts of Assets Presented in the Balance Sheet	0	501
Gross Amounts of Recognized (Liabilities)	(1,407)	0
Gross Amounts Offset in the Balance Sheet	19	1,028
Net Amounts of (Liabilities) Presented in the Balance Sheet	$ (1,388)	$ 1,028

Fair value of liability associated with 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.

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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, after offset of derivative liability, of 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, before offset against an obligation to return collateral under a master netting arrangement. 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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Fair value, after offset of derivative asset, of 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, elected not to be and before offset against a right to receive collateral under a master netting arrangement. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

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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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