Land, Buildings, Equipment and Software, Net - Depreciation Expense, Operating Lease Rent Expense, Minimum Operating Lease Commitments (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Land, Buildings, Equipment and Software, Net [Abstract]
Depreciation expense	$ 431		$ 452		$ 405
Operating lease rent expense	754	[1]	646	[1]	681	[1]
Capital Leased Assets, Gross	150		80
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Operating Leases, Future Minimum Payments Due, Current	579
Operating Leases, Future Minimum Payments, Due in Two Years	467
Operating Leases, Future Minimum Payments, Due in Three Years	304
Operating Leases, Future Minimum Payments, Due in Four Years	122
Operating Leases, Future Minimum Payments, Due in Five Years	72
Operating Leases, Future Minimum Payments, Due Thereafter	$ 92

[1] (1)We lease certain land, buildings and equipment, substantially all of which are accounted for as operating leases. Capital leased assets were approximately $150 and $80 at December 31, 2013 and 2012, respectively.