Fair Value Measurements Assets Fair Value Nonrecurring Basis (Details) (Fair Value, Measurements, Nonrecurring [Member], Fair Value, Inputs, Level 3 [Member], USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of property, plant, and equipment impaired during the period	$ 77	$ 39
Fair value of intangible assets measured on a non-recurring basis that was written down during the period	$ 56	$ 48