Fair Value Measurements (Details) (Fair Value, Measurements, Recurring, USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Assets
Derivative financial instruments, net	$ 128	$ 223	$ 232
Total Assets	128	223	232
Liabilities
Guarantees	1	2	2
Total liabilities	1	2	2
Level 1
Assets
Derivative financial instruments, net	0	0	0
Total Assets	0	0	0
Liabilities
Guarantees	0	0	0
Total liabilities	0	0	0
Level 2
Assets
Derivative financial instruments, net	128	223	232
Total Assets	128	223	232
Liabilities
Guarantees	0	0	0
Total liabilities	0	0	0
Level 3
Assets
Derivative financial instruments, net	0	0	0
Total Assets	0	0	0
Liabilities
Guarantees	1	2	2
Total liabilities	$ 1	$ 2	$ 2