Equity Level 4 Capital Purchase Program (Details) (USD $) In Millions, except Share data, unless otherwise specified	1 Months Ended	12 Months Ended			3 Months Ended
	Jul. 29, 2014	Dec. 31, 2013	Dec. 31, 2014	Dec. 31, 2012	Dec. 31, 2014
Class of Stock [Line Items]
Stock Repurchase Program, Authorized Amount			2,775		2,775
Stock Repurchase Program, Remaining Authorized Repurchase Amount			979		979
Exercise price of warrant		$ 9.504	9.388	9.599	9.388
Proceeds from Warrant Exercises		33
Class of Warrant or Right, Outstanding		32,400,000	7,200,000		7,200,000
Treasury stock acquired	$ (165)
Warrant [Member]
Class of Stock [Line Items]
Stock Issued During Period, Shares, Warrant Exercised		18,100,000	25,200,000
Common Stock [Member]
Class of Stock [Line Items]
Treasury stock acquired		(19,235,000)	(49,518,000)	(8,045,000)
Accelerated Share Repurchase Program [Member]
Class of Stock [Line Items]
Stock Repurchased During Period, Shares					1,600,000