Operating Leases, Commitments and Contingencies, and Guarantees (Future Minimum Lease Payments and Sublease Receipts) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011
Operating lease, future minimum payments, current	$ 37
Operating lease, future minimum payments, due in two years	37
Operating lease, future minimum payments, due in three years	31
Operating lease, future minimum payments, due in four years	24
Operating lease, future minimum payments, due in five years	21
Operating lease, future minimum payments, thereafter	72
Operating lease, future minimum payments, total	222
Operating lease, future minimum receipts, current	2
Operating lease, future minimum receipts, in two years	2
Operating lease, future minimum receipts, in three years
Operating lease, future minimum receipts, in four years
Operating lease, future minimum receipts, in five years
Operating lease, future minimum receipts, thereafter
Operating lease, future minimum receipts, total	$ 4