Long-term Commitments (Operating Lease Agreements) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013
Gross Rental Commitments
2014, Net Rental Commitments	$ 398
2015, Gross Rental Commitments	357
2016, Gross Rental Commitments	318
2017, Gross Rental Commitments	273
2018, Gross Rental Commitments	244
Subsequent years, Gross Rental Commitments	1,101
Rental from Subleases
2014, Rentals from Subleases	52
2015, Rentals from Subleases	46
2016, Rentals from Subleases	45
2017, Rentals from Subleases	42
2018, Rentals from Subleases	40
Subsequent years, Rentals from Subleases	86
Net Rental Commitments
2014, Net Rental Commitments	346
2015, Net Rental Commitments	311
2016, Net Rental Commitments	273
2017, Net Rental Commitments	231
2018, Net Rental Commitments	204
Subsequent years, Net Rental Commitments	$ 1,015

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Amount of required minimum rental payments maturing in the next fiscal year following the latest fiscal year for operating leases having an initial or remaining non-cancelable letter-terms in excess of one year.

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