Segment Information - Revenue by Geographic Area (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Revenue	$ 8,541	$ 8,504	$ 24,689	$ 24,636
Operating Segments
Segment Reporting Information [Line Items]
Revenue	8,541	8,504	24,689	24,636
Operating Segments | North America
Segment Reporting Information [Line Items]
Revenue	2,850	3,189	8,389	9,164
Operating Segments | Latin America
Segment Reporting Information [Line Items]
Revenue	1,014	978	3,121	2,767
Operating Segments | Europe/CIS/Africa
Segment Reporting Information [Line Items]
Revenue	2,062	1,820	5,665	5,316
Operating Segments | Middle East & Asia
Segment Reporting Information [Line Items]
Revenue	2,553	2,417	7,343	7,079
Eliminations & other
Segment Reporting Information [Line Items]
Revenue	$ 62	$ 100	$ 171	$ 310