Supplemental Cash Flow Information - Summary of Cash Paid (Received) for Interest and Income Taxes and Non-cash Investing and Financing Activities (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Cash paid (received)
Interest, net of amounts capitalized	$ 371	$ 326
Income taxes, net of refunds	18	12
Non-cash investing activities
Fair value of properties and equipment acquired	0	2
Asset retirement cost additions	71	63
Accruals of property, plant, and equipment	781	965
Net liabilities assumed (divested) in acquisitions and divestitures	0	$ (25)
Non-cash investing and financing activities
Finance leases	$ 6