Segments and Geographic Information Segment and Geographic Information ( Revenue by Segment) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	$ 3,544	$ 3,542	$ 3,229	$ 3,271	$ 3,219	$ 3,522	$ 3,656	$ 3,758	$ 13,586	$ 14,155	$ 16,124
Corporate, Non-Segment [Member] | Corporate and Other
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues									77	31	15
Intersegment Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues									(23)	(44)	(25)
Operating Segments [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues									13,586	14,155	16,124
Operating Segments [Member] | US SBU
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues									3,429	3,593	3,826
Operating Segments [Member] | Andes SBU
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues									2,506	2,489	2,642
Operating Segments [Member] | Brazil SBU
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues									3,755	3,858	4,987
Operating Segments [Member] | MCAC SBU
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues									2,172	2,353	2,682
Operating Segments [Member] | Europe SBU
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues									918	1,191	1,439
Operating Segments [Member] | Asia SBU
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues									$ 752	$ 684	$ 558