Fair Value of Derivative Instruments on Condensed Consolidated Balance Sheets (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Derivatives, Fair Value [Line Items]
Derivative Asset, Current	$ 117,369	$ 4,131
Derivative liabilities	74,583	23,450
Derivative Asset, Noncurrent	4,053	2,750
Derivative Liability, Noncurrent	8,900	3,385
Derivative Liability	83,483	26,835
Derivative Asset	121,422	6,881
Commodity contracts
Derivatives, Fair Value [Line Items]
Derivative Asset	45,100
Commodity contracts \| Current Derivative Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Current	117,369	4,131
Derivative liabilities	71,634	23,450
Commodity contracts \| Noncurrent Derivative Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Noncurrent	4,053	2,750
Derivative Liability, Noncurrent	4,658	3,385
Interest Rate Swap
Derivatives, Fair Value [Line Items]
Derivative Liability	7,200
Interest Rate Swap \| Current Derivative Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Current	0	0
Derivative liabilities	2,949	0
Interest Rate Swap \| Noncurrent Derivative Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Noncurrent	0	0
Derivative Liability, Noncurrent	4,242	0
Fair Value, Measurements, Recurring \| Commodity contracts
Derivatives, Fair Value [Line Items]
Derivative Asset, Current	117,369	4,131
Derivative liabilities	71,634	(23,450)
Derivative Asset, Noncurrent	4,053	2,750
Derivative Liability, Noncurrent	4,658	$ 3,385
Fair Value, Measurements, Recurring \| Interest Rate Swap
Derivatives, Fair Value [Line Items]
Derivative Asset, Current	0
Derivative liabilities	2,949
Derivative Asset, Noncurrent	0
Derivative Liability, Noncurrent	$ 4,242

Fair value, after the 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 not subject to a master netting arrangement and not elected to be offset.

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