Derivative Instruments (Detail 3) (Details) - USD ($) $ in Millions		Jun. 30, 2020		Dec. 31, 2019
Derivative Instruments Subject to Master Netting Arrangement [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		$ 78
Derivative assets, current	[1]	199	[2]	$ 156	[3]
Derivative Asset, Noncurrent	[1]	250	[2]	246	[3]
Long-term derivative liabilities	[1]	(196)	[2]	(63)	[3]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement				0
Derivative Liability, Collateral, Right to Reclaim Cash, Offset		7		114
Derivative Liability, Current	[1]	(168)	[2]	(225)	[3]
Derivative Liability	[1]	(364)		(288)
Derivative, Collateral, Right to Reclaim Cash		260		191
Derivative, Fair Value, Net	[1]	85		114
Derivative Asset	[1]	449		402
Derivative Financial Instruments, Assets [Member]
Derivative Instruments Subject to Master Netting Arrangement [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		1,779		1,423
Derivative Asset, Collateral, Obligation to Return Cash, Offset		(1,330)		(1,021)
Commodity exchange traded derivatives contracts
Derivative Instruments Subject to Master Netting Arrangement [Line Items]
Derivative assets, current	[1]	0		0
Derivative Asset, Noncurrent	[1]	0		0
Long-term derivative liabilities	[1]	0		0
Derivative Liability, Current	[1]	0		0
Derivative Liability		(1,001)		(984)
Derivative Asset		991		872
Commodity forward contracts
Derivative Instruments Subject to Master Netting Arrangement [Line Items]
Derivative assets, current	[1]	199		154
Derivative Asset, Noncurrent	[1]	250		236
Long-term derivative liabilities	[1]	(84)		(45)
Derivative Liability, Current	[1]	(119)		(212)
Derivative Liability	[4]	(539)		(408)
Derivative Asset	[4]	788		539
Interest rate hedging instruments
Derivative Instruments Subject to Master Netting Arrangement [Line Items]
Derivative assets, current	[1]	0		2
Derivative Asset, Noncurrent	[1]	0		10
Long-term derivative liabilities	[1]	(112)		(18)
Derivative Liability, Current	[1]	(49)		(13)
Derivative Liability		(161)		(31)
Derivative Asset		0		12
Level 3
Derivative Instruments Subject to Master Netting Arrangement [Line Items]
Margin/Cash (Received) Posted Subject to Master Netting Arrangement		0		0
Level 3 | Commodity exchange traded derivatives contracts
Derivative Instruments Subject to Master Netting Arrangement [Line Items]
Derivative Liability		0		0
Derivative Asset		0		0
Level 3 | Commodity forward contracts
Derivative Instruments Subject to Master Netting Arrangement [Line Items]
Derivative Liability	[4]	(118)		(123)
Derivative Asset	[4]	364		294
Level 3 | Interest rate hedging instruments
Derivative Instruments Subject to Master Netting Arrangement [Line Items]
Derivative Liability		0		0
Derivative Asset		0		0
Derivative Assets, Current [Member]
Derivative Instruments Subject to Master Netting Arrangement [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		1,198	[2]	991	[3]
Derivative Asset, Collateral, Obligation to Return Cash, Offset		(999)	[2]	(835)	[3]
Derivative Assets, Current [Member] | Commodity exchange traded derivatives contracts
Derivative Instruments Subject to Master Netting Arrangement [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		758		727
Derivative Asset, Collateral, Obligation to Return Cash, Offset		(758)		(727)
Derivative Assets, Current [Member] | Commodity forward contracts
Derivative Instruments Subject to Master Netting Arrangement [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		440		262
Derivative Asset, Collateral, Obligation to Return Cash, Offset		(241)		(108)
Derivative Assets, Current [Member] | Interest rate hedging instruments
Derivative Instruments Subject to Master Netting Arrangement [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		0		2
Derivative Asset, Collateral, Obligation to Return Cash, Offset		0		0
Derivative Assets, Non-current [Member]
Derivative Instruments Subject to Master Netting Arrangement [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		581	[2]	432	[3]
Derivative Asset, Collateral, Obligation to Return Cash, Offset		(331)	[2]	(186)	[3]
Derivative Assets, Non-current [Member] | Commodity exchange traded derivatives contracts
Derivative Instruments Subject to Master Netting Arrangement [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		233		145
Derivative Asset, Collateral, Obligation to Return Cash, Offset		(233)		(145)
Derivative Assets, Non-current [Member] | Commodity forward contracts
Derivative Instruments Subject to Master Netting Arrangement [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		348		277
Derivative Asset, Collateral, Obligation to Return Cash, Offset		(98)		(41)
Derivative Assets, Non-current [Member] | Interest rate hedging instruments
Derivative Instruments Subject to Master Netting Arrangement [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		0		10
Derivative Asset, Collateral, Obligation to Return Cash, Offset		0		0
Derivative Liabilities, Current [Member]
Derivative Instruments Subject to Master Netting Arrangement [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		(1,139)	[2]	(1,164)	[3]
Derivative Liability, Collateral, Right to Reclaim Cash, Offset		971	[2]	939	[3]
Derivative Liabilities, Current [Member] | Commodity exchange traded derivatives contracts
Derivative Instruments Subject to Master Netting Arrangement [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		(733)		(830)
Derivative Liability, Collateral, Right to Reclaim Cash, Offset		733		830
Derivative Liabilities, Current [Member] | Commodity forward contracts
Derivative Instruments Subject to Master Netting Arrangement [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		(357)		(321)
Derivative Liability, Collateral, Right to Reclaim Cash, Offset		238		109
Derivative Liabilities, Current [Member] | Interest rate hedging instruments
Derivative Instruments Subject to Master Netting Arrangement [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		(49)		(13)
Derivative Liability, Collateral, Right to Reclaim Cash, Offset		0		0
Derivative Liabilities, Non-current [Member]
Derivative Instruments Subject to Master Netting Arrangement [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		(562)	[2]	(259)	[3]
Derivative Liability, Collateral, Right to Reclaim Cash, Offset		366	[2]	196	[3]
Derivative Liabilities, Non-current [Member] | Commodity exchange traded derivatives contracts
Derivative Instruments Subject to Master Netting Arrangement [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		(268)		(154)
Derivative Liability, Collateral, Right to Reclaim Cash, Offset		268		154
Derivative Liabilities, Non-current [Member] | Commodity forward contracts
Derivative Instruments Subject to Master Netting Arrangement [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		(182)		(87)
Derivative Liability, Collateral, Right to Reclaim Cash, Offset		98		42
Derivative Liabilities, Non-current [Member] | Interest rate hedging instruments
Derivative Instruments Subject to Master Netting Arrangement [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		(112)		(18)
Derivative Liability, Collateral, Right to Reclaim Cash, Offset		0		0
Derivative Financial Instruments, Liabilities [Member]
Derivative Instruments Subject to Master Netting Arrangement [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		(1,701)		(1,423)
Derivative Liability, Collateral, Right to Reclaim Cash, Offset		$ 1,337		$ 1,135

[1] At June 30, 2020 and December 31, 2019, we had $260 million and $191 million, respectively, of collateral under master netting arrangements that were not offset against our derivative instruments on the Consolidated Condensed Balance Sheets primarily related to initial margin requirements.

[2] At June 30, 2020, current and long-term derivative assets are shown net of collateral of $(28) million and $(9) million, respectively, and current and long-term derivative liabilities are shown net of collateral of $1 million and $43 million, respectively.

[3] At December 31, 2019, current and long-term derivative assets are shown net of collateral of $(4) million and $(4) million, respectively, and current and long-term derivative liabilities are shown net of collateral of $108 million and $14 million, respectively.

[4] Includes OTC swaps and options.