Goodwill and Other Intangible Assets - Gross Carrying Amount, Accumulated Amortization And Net Carrying Amount Of Other Intangible Assets (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014	Dec. 31, 2013
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 3,332	$ 3,471
Accumulated Amortization	(1,512)	(1,446)
Net Carrying Amount	1,820	2,025	$ 2,121	$ 2,360
Client relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	2,503	2,569
Accumulated Amortization	(1,175)	(1,088)
Net Carrying Amount	1,328	1,481
Core deposits
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	672	688
Accumulated Amortization	(239)	(219)
Net Carrying Amount	433	469
Other
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	157	214
Accumulated Amortization	(98)	(139)
Net Carrying Amount	$ 59	$ 75