Goodwill and Other Intangible Assets (Changes in Goodwill by Business Segment) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Goodwill [Line Items]
Goodwill, Beginning Balance	$ 9,074	$ 9,072
Other	29	2
Goodwill, Ending Balance	9,103	9,074
Retail Banking [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance		5,794
Other		1
Goodwill, Ending Balance	5,795	5,795
Corporate & Institutional Banking [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance	3,215	3,214
Other	29	1
Goodwill, Ending Balance	3,244	3,215
Asset Management Group [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance			64
Goodwill, Ending Balance	$ 64	$ 64	$ 64