Debt (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Debt
Short-term loans	$ 2	$ 0
Current maturities of long-term debt and other	0	10
Short-term debt and current maturities of long-term debt	2	10
Non-current maturities of long-term debt	4	1,256
Non-current capital leases	0	57
Deferred gain on interest rate swaps	0	45
Unamortized discounts and debt issuance costs	0	(8)
Long-term debt	4	1,350
Total debt	$ 6	$ 1,360