Leased Vehicles Minimum rental payments (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013
Operating Leases, Future Minimum Payments Receivable [Abstract]
Operating Leases, Future Minimum Payments Receivable, Current	$ 628
Operating Leases, Future Minimum Payments Receivable, in Two Years	512
Operating Leases, Future Minimum Payments Receivable, in Three Years	266
Operating Leases, Future Minimum Payments Receivable, in Four Years	43
Operating Leases, Future Minimum Payments Receivable, in Five Years	$ 4