Operating Leases, Commitments and Contingencies, and Guarantees (Future Minimum Lease Payments and Sublease Receipts) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012
Operating Leases, Future Minimum Payments Due, Next Twelve Months	$ 39
Operating Leases, Future Minimum Payments, Due in Two Years	33
Operating Leases, Future Minimum Payments, Due in Three Years	25
Operating Leases, Future Minimum Payments, Due in Four Years	24
Operating Leases, Future Minimum Payments, Due in Five Years	17
Operating Leases, Future Minimum Payments, Due Thereafter	72
Operating Leases, Future Minimum Payments Due	210
Operating Leases, Future Minimum Payments Receivable, Current	2
Operating Leases, Future Minimum Payments Receivable, in Two Years
Operating Leases, Future Minimum Payments Receivable, in Three Years
Operating Leases, Future Minimum Payments Receivable, in Four Years
Operating Leases, Future Minimum Payments Receivable, in Five Years
Operating Leases, Future Minimum Payments Receivable, Thereafter
Operating Leases, Future Minimum Payments Receivable	$ 2