Goodwill and Intangible Assets Goodwill and Intangible Assets (Summary of Changes in Carrying Value of Goodwill) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2012	Dec. 31, 2010
Goodwill [Line Items]
Balance	$ 635	$ 635	$ 150
Sterling acquisition	485
Business Bank
Goodwill [Line Items]
Balance	380	380	90
Sterling acquisition	290
Retail Bank
Goodwill [Line Items]
Balance	194	194	47
Sterling acquisition	147
Wealth Management
Goodwill [Line Items]
Balance	61	61	13
Sterling acquisition	$ 48