Net Payments and Proceeds on Other Debt (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Debt [Abstract]
Proceeds from short-term debt			$ 742	$ 351
Proceeds from issuance of long-term debt			1,112	1,030
Repayments of long-term debt			(1,112)	(779)
Net Proceeds on Debt	$ 199	$ (101)	$ 742	$ 602