Segment Information - Revenue by Geographic Area (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Revenue	$ 23,601	$ 32,917	$ 32,815
Operating Segments
Segment Reporting Information [Line Items]
Revenue	23,601	32,917	32,815
Operating Segments | North America
Segment Reporting Information [Line Items]
Revenue	5,478	10,446	11,730
Operating Segments | Latin America
Segment Reporting Information [Line Items]
Revenue	3,472	4,544	4,013
Operating Segments | Europe/CIS/Africa
Segment Reporting Information [Line Items]
Revenue	5,963	7,682	7,113
Operating Segments | Middle East & Asia
Segment Reporting Information [Line Items]
Revenue	8,567	10,016	9,582
Eliminations & other
Segment Reporting Information [Line Items]
Revenue	$ 121	$ 229	$ 377