Fair Value Measurements (Details) (Recurring basis, USD $) In Millions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Assets
Derivative financial instruments, net	$ 107	$ 128
Total Assets	107	128
Liabilities
Guarantees	1	1
Total Liabilities	1	1
Level 1
Assets
Derivative financial instruments, net	0	0
Total Assets	0	0
Liabilities
Guarantees	0	0
Total Liabilities	0	0
Level 2
Assets
Derivative financial instruments, net	107	128
Total Assets	107	128
Liabilities
Guarantees	0	0
Total Liabilities	0	0
Level 3
Assets
Derivative financial instruments, net	0	0
Total Assets	0	0
Liabilities
Guarantees	1	1
Total Liabilities	$ 1	$ 1