Fair Value Measurements (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Level 3
Liabilities
Guarantees	$ 1	$ 1
Recurring basis
Assets
Derivative financial instruments, net	97	128
Total Assets	97	128
Liabilities
Guarantees	1	1
Total Liabilities	1	1
Recurring basis | Level 1
Assets
Derivative financial instruments, net	0	0
Total Assets	0	0
Liabilities
Guarantees	0	0
Total Liabilities	0	0
Recurring basis | Level 2
Assets
Derivative financial instruments, net	97	128
Total Assets	97	128
Liabilities
Guarantees	0	0
Total Liabilities	0	0
Recurring basis | Level 3
Assets
Derivative financial instruments, net	0	0
Total Assets	0	0
Liabilities
Guarantees	1	1
Total Liabilities	$ 1	$ 1