Derivatives and Other Financial Instruments - Schedule of Detail for Level 1, 2 and 3 Derivatives (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative Assets	$ 74	$ 153
Derivative Liabilities	615	289
Derivative Assets Current	59	73
Derivative Liabilities Current	67	82
Derivative Assets Noncurrent	18	82
Derivative Liabilities Noncurrent	581	261
Unrealized gain (loss) recognized in Other comprehensive (loss) income	(437)	803
Realized gain (loss) reclassed from Other comprehensive (loss) income to earnings	(22)	(77)
Non-controlling and Equity Interest [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Unrealized gain (loss) recognized in Other comprehensive (loss) income	(38)	5
Realized gain (loss) reclassed from Other comprehensive (loss) income to earnings	(38)	(25)
Level 1 and 2 Derivative Instruments [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative Assets	3	2
Derivative Liabilities	33	54
Unrealized gain (loss) recognized in Other comprehensive (loss) income	(14)	24
Realized gain (loss) reclassed from Other comprehensive (loss) income to earnings	(26)	(14)
Level 3 Derivative Instruments [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative Assets	74	153
Derivative Liabilities	615	289
Unrealized gain (loss) recognized in Other comprehensive (loss) income	(385)	774
Realized gain (loss) reclassed from Other comprehensive (loss) income to earnings	42	(38)	$ (82)
Level 1, 2 and 3 Derivative Instruments [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative Assets	77	155
Derivative Liabilities	648	343
Derivative Assets Current	59	73
Derivative Liabilities Current	67	82
Derivative Assets Noncurrent	18	82
Derivative Liabilities Noncurrent	$ 581	$ 261