Goodwill and Other Intangibles (Amortized Intangible Assets) (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Gross Cost	$ 1,379	$ 1,457
Accumulated Amortization	424	421
Net Carrying Amount	955	1,036
Other Intangible Assets
Finite-Lived Intangible Assets [Line Items]
Gross Cost	150	176
Accumulated Amortization	65	74
Net Carrying Amount	85	102
Customer Lists
Finite-Lived Intangible Assets [Line Items]
Gross Cost	1,229	1,281
Accumulated Amortization	359	347
Net Carrying Amount	$ 870	$ 934