Goodwill and Intangible Assets (Schedules for Amortization Expense) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Finite Lived Intangible Assets
Amortization expense for acquired intangible assets	$ 59	$ 60	$ 179	$ 176
Expected amortization expense for acquired intangible assets recorded as of balance sheet date
Remainder of 2013	59		59
2014	214		214
2015	200		200
2016	186		186
2017	171		171
2018	154		154
After 2018	$ 632		$ 632