Goodwill and Other Intangible Assets (Amortization Expense on Existing Intangible Assets) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Goodwill and Other Intangible Assets Disclosure [Abstract]
Amortization expense	$ 86	$ 96
Future amortization expense to be recognized during remainder of 2015	28
Future amortization expense to be recognized during 2016	97
Future amortization expense to be recognized during 2017	83
Future amortization expense to be recognized during 2018	72
Future amortization expense to be recognized during 2019	61
Future amortization expense to be recognized during 2020	$ 37