Commitments and Contingencies (Schedule of Variable Interest Entities) (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Variable Interest Entity [Line Items]
Property, plant and equipment, net	$ 3,391	$ 3,350
Trade payables	739	649
Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Property, plant and equipment, net	113	118
Trade payables	50	41
Current installments of long-term debt	8	7
Long-term debt	137	140
Total	195	188
Maximum exposure to loss	$ 315	$ 273