Financial Risk Management Activities - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Derivative Instruments Gain Loss [Line Items]
Amount of terminated interest rate swaps		$ 350,000,000
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 - (increase) decrease in derivative liability	1,000,000	(3,000,000)
Payment to terminate interest rate swaps		3,000,000
Foreign Exchange
Derivative Instruments Gain Loss [Line Items]
Outstanding gross notional amount	43,000,000		$ 16,000,000
Foreign exchange gains reported in Other, net in Revenues and Non-Operating Income in the Statement of Consolidated Income	5,000,000	4,000,000
Gain (Loss) on foreign exchange contracts not designated as hedging instruments		2,000,000
Foreign Exchange | Maximum
Derivative Instruments Gain Loss [Line Items]
Gain (Loss) on foreign exchange contracts not designated as hedging instruments	(1,000,000)
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	(15,000,000)	(30,000,000)
Pre-tax deferred income (losses) in Accumulated other comprehensive income (loss) to be reclassified into earnings during the remainder of 2019	$ 3,000,000
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		$ (8,000,000)