Fair Value Fair Value (Details 4) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Fair Value of Financial Instruments [Line Items]
Notes Receivable, excluding Capital Leases	$ 42	$ 48
Notes receivable, excluding capital leases		48
Dividends Payable Fair Value Disclosure		99
Dividends Payable, Current	107	99
Short-term borrowing		419
Short-term Debt	98	419
Long-term debt		8,757
Long-term Debt	7,735	7,682
Fair Value, Inputs, Level 1 [Member]
Fair Value of Financial Instruments [Line Items]
Notes receivable, excluding capital leases	0
Dividends Payable Fair Value Disclosure	107
Short-term borrowing	0
Long-term debt	314
Fair Value, Inputs, Level 2 [Member]
Fair Value of Financial Instruments [Line Items]
Notes receivable, excluding capital leases	0
Dividends Payable Fair Value Disclosure	0
Short-term borrowing	98
Long-term debt	7,998
Fair Value, Inputs, Level 3 [Member]
Fair Value of Financial Instruments [Line Items]
Notes receivable, excluding capital leases	42
Dividends Payable Fair Value Disclosure	0
Short-term borrowing	0
Long-term debt	$ 612