Commitments and Contingencies (Schedule of Variable Interest Entities) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Variable Interest Entity [Line Items]
Property, plant and equipment, net	$ 3,265	$ 3,269
Trade payables	688	673
Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Property, plant and equipment, net	113	119
Trade payables	37	40
Current installments of long-term debt	6	6
Long-term debt	136	137
Total	179	183
Maximum exposure to loss	$ 232	$ 228