Fair Value Measurements (Details 3-Reported) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Fair Value [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Other noncurrent financial assets	$ 168	$ 189
Total financial assets	168	189
Financial liabilities
Other current financial liabilities	13	13
Long-term debt, including current portion	6,941	7,610
Deferred credits and other financial liabilities	164	94
Financial Liabilities Fair Value Disclosure	7,118	7,717
Carrying Amount [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Other noncurrent financial assets	165	186
Total financial assets	165	186
Financial liabilities
Other current financial liabilities	13	13
Long-term debt, including current portion	6,461	6,642
Deferred credits and other financial liabilities	161	94
Financial Liabilities Fair Value Disclosure	$ 6,635	$ 6,749