Goodwill and Other Intangibles (Amortized Intangible Assets) (Details) - USD ($) $ in Millions		Sep. 30, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Gross Cost		$ 1,350	$ 1,457
Accumulated Amortization		443	421
Net Carrying Amount		907	1,036
Client relationships
Finite-Lived Intangible Assets [Line Items]
Gross Cost		1,202	1,281
Accumulated Amortization		371	347
Net Carrying Amount		831	934
Other Intangible Assets
Finite-Lived Intangible Assets [Line Items]
Gross Cost	[1]	148	176
Accumulated Amortization	[1]	72	74
Net Carrying Amount	[1]	$ 76	$ 102

[1] Primarily non-compete agreements, trade names and developed technology.