Segment Information - Revenue by Geographic Area (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Segment Reporting Information [Line Items]
Revenue	$ 8,303	$ 7,462	$ 16,131	$ 14,356
Operating Segments
Segment Reporting Information [Line Items]
Revenue	8,303	7,462	16,131	14,356
Operating Segments | North America
Segment Reporting Information [Line Items]
Revenue	3,139	2,202	5,974	4,074
Operating Segments | Latin America
Segment Reporting Information [Line Items]
Revenue	919	1,039	1,790	1,991
Operating Segments | Europe/CIS/Africa
Segment Reporting Information [Line Items]
Revenue	1,778	1,750	3,482	3,401
Operating Segments | Middle East & Asia
Segment Reporting Information [Line Items]
Revenue	2,367	2,347	4,676	4,666
Eliminations & other
Segment Reporting Information [Line Items]
Revenue	$ 100	$ 124	$ 209	$ 224