Financial Risk Management Activities - Corporate Financial Risk Management Activities - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Derivative Instruments Gain Loss [Line Items]
Cumulative currency translation gain (losses) recognized in earnings	$ 0	$ 0	$ (900,000,000)
Interest Rate Swaps | Designated as Fair Value Hedges
Derivative Instruments Gain Loss [Line Items]
Outstanding gross notional amount	100,000,000	100,000,000
Unrealized change in fair value of interest rate swaps - decrease in derivative liability	(3,000,000)	1,000,000	4,000,000
Amount of terminated interest rate swaps		350,000,000
Payment to terminate interest rate swaps		3,000,000
Foreign Exchange
Derivative Instruments Gain Loss [Line Items]
Outstanding gross notional amount	90,000,000	16,000,000
Total foreign exchange gains and (losses) reported in Other, net in Revenues and Non-Operating Income in the Statement of Consolidated Income	3,000,000	(5,000,000)	15,000,000
Gain (Loss) on foreign exchange contracts not designated as hedging instruments	(2,000,000)	(2,000,000)	3,000,000
After tax foreign currency translation adjustments included in Accumulated other comprehensive income (loss)			144,000,000
Cumulative currency translation gain (losses) recognized in earnings			(900,000,000)
Derivative Contracts Designated as Hedging Instruments | Crude Oil
Derivative Instruments Gain Loss [Line Items]
Increased (decreased) sales and other operating revenue	1,000,000	(161,000,000)	(34,000,000)
Pre-tax deferred income (losses) in Accumulated other comprehensive income (loss) to be reclassified into earnings during the next 12 months	$ (98,000,000)
Derivative Contracts Not Designated as Hedging Instruments | Crude Oil
Derivative Instruments Gain Loss [Line Items]
Crude oil price hedging contracts decreased sales and other operating revenues by this amount, pre-tax		$ (22,000,000)	$ (25,000,000)