Commitments and Contingencies (Schedule of Variable Interest Entities) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Variable Interest Entity [Line Items]
Property, plant and equipment, net	$ 3,325	$ 3,350
Trade payables	716	649
Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Property, plant and equipment, net	115	118
Trade payables	44	41
Current installments of long-term debt	8	7
Long-term debt	138	140
Total	190	188
Maximum exposure to loss	$ 304	$ 273