Financial Risk Management Activities - Corporate Financial Risk Management Activities - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Derivative Instruments Gain Loss [Line Items]
Amount of terminated interest rate swaps	$ 350,000,000
Cumulative currency translation gain (losses) recognized in earnings	0	$ (900,000,000)	$ 0
Interest Rate Swaps | Designated as Fair Value Hedges
Derivative Instruments Gain Loss [Line Items]
Outstanding gross notional amount	100,000,000	450,000,000
Amount of cash proceeds received from settled interest rate swaps		0	5,000,000
Unrealized change in fair value of interest rate swaps - increase in derivative liability/(increase in asset)	(1,000,000)	(4,000,000)	6,000,000
Payment to terminate interest rate swaps	3,000,000
Interest Rate Swaps | Designated as Cash Flow Hedges
Derivative Instruments Gain Loss [Line Items]
Outstanding gross notional amount		553,000,000
Payment to settle interest rate swaps		3,000,000
Foreign Exchange
Derivative Instruments Gain Loss [Line Items]
Outstanding gross notional amount	16,000,000	52,000,000
Total foreign exchange gains and (losses) reported in Other, net in Revenues and Non-Operating Income in the Statement of Consolidated Income	(5,000,000)	15,000,000	26,000,000
Gain (Loss) on foreign exchange contracts not designated as hedging instruments	(2,000,000)	3,000,000	62,000,000
After tax foreign currency translation adjustments included in Accumulated other comprehensive income (loss)		144,000,000	56,000,000
Derivative Contracts Designated as Hedging Instruments | Crude Oil
Derivative Instruments Gain Loss [Line Items]
Crude oil price hedging contracts increased (decreased) sales and other operating revenues by this amount, pre-tax	161,000,000	34,000,000	$ 0
Pre-tax deferred income (losses) in Accumulated other comprehensive income (loss) to be reclassified into earnings during the next 12 months	365,000,000
Derivative Contracts Not Designated as Hedging Instruments | Crude Oil
Derivative Instruments Gain Loss [Line Items]
Crude oil price hedging contracts increased (decreased) sales and other operating revenues by this amount, pre-tax	$ (22,000,000)	$ (25,000,000)