Leases Rentals and Outsourced Service Arrangements (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Leases Rentals And Outsourced Service Arrangements [Line Items]
Rental expense for operating leases	$ 120	$ 130	$ 115
Future net minimum rental payments under non-cancelable operating leases	641
Future minimum rental payments under non-cancelable operating leases payable in one year	131
Future minimum rental payments under non-cancelable operating leases payable in two years	127
Future minimum rental payments under non-cancelable operating leases payable in three years	105
Future minimum rental payments under non-cancelable operating leases payable in four years	75
Future minimum rental payments under non-cancelable operating leases payable in five years	59
Future minimum rental payments under non-cancelable operating leases payable after five years	$ 144