Commitments and Contingencies (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Future Minimum Rental Payments
Operating leases minimum payments due in 2014	$ 305
Operating leases minimum payments due in 2015	230
Operating leases minimum payments due in 2016	162
Operating leases minimum payments due in 2017	111
Operating leases minimum payments due in 2018	95
Operating leases minimum payments due - Thereafter	321
Total minimum rental payments under operating leases	1,224
Minimum rentals to be received under subleases	21
Rental Expense
Minimum rental expense	574	508	523
Contingent rental expense	7	23	23
Total rental expense	581	531	546
Less sublease rental income	0	(2)	(2)
Net rental expense	581	529	544
Commitments and Contingencies (Textual)
Minimum range of possible loss contingency	0
Maximum range of possible loss contingency	$ 200