Segments and Geographic Information Segment and Geographic Information (Revenue and Assets by Country) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 17,146	$ 15,891	$ 17,164
Property, plant and equipment, net	25,151	25,112
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	3,828	3,630	3,736
Property, plant and equipment, net	7,713	7,523
United States | Discontinued Operations
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	2	23	63
Property, plant and equipment, net		69
Total Non-U.S.
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	13,318	12,261	13,428
Property, plant and equipment, net	17,438	17,589
Brazil
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	6,009	5,015	5,788
Property, plant and equipment, net	4,725	5,293
Chile
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	1,624	1,569	1,679
Property, plant and equipment, net	4,012	3,312
El Salvador
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	832	860	854
Property, plant and equipment, net	304	292
Dominican Republic
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	802	832	761
Property, plant and equipment, net	702	689
Colombia
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	552	523	453
Property, plant and equipment, net	430	412
United Kingdom
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	533	558	505
Property, plant and equipment, net	324	603
Argentina
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	463	545	857
Property, plant and equipment, net	222	256
Philippines
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	451	497	559
Property, plant and equipment, net	752	776
Mexico
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	434	440	397
Property, plant and equipment, net	733	748
Bulgaria
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	410	422	369
Property, plant and equipment, net	1,457	1,606
Puerto Rico
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	348	328	293
Property, plant and equipment, net	551	562
Panama
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	263	250	266
Property, plant and equipment, net	1,030	1,028
Jordan
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	262	142	121
Property, plant and equipment, net	484	439
Kazakhstan
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	161	156	151
Property, plant and equipment, net	206	183
Sri Lanka
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	107	53	169
Property, plant and equipment, net	7	7
Spain
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	0	0	119
Property, plant and equipment, net	0	0
Cameroon
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	0	0	0
Property, plant and equipment, net	0	0
Cameroon | Discontinued Operations
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	230	473	457
Property, plant and equipment, net		1,100
Ukraine
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	0	0	0
Property, plant and equipment, net	0	0
Ukraine | Discontinued Operations
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue		187	491
Hungary
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	0	0	0
Property, plant and equipment, net	0	0
Hungary | Discontinued Operations
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue			18
Vietnam
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	0	0	0
Property, plant and equipment, net	1,491	1,296
Other Non-U.S.
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	67	71	87
Property, plant and equipment, net	8	87
Other Non-U.S. | Discontinued Operations
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue		6	11
Property, plant and equipment, net		$ 19