Variable Interest Entities and Securitization Activities (Proceeds from retained interests in securitization transactions) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Securitization Activities and Variable Interest Entities [Abstract]
Proceeds received from new securitization transactions	$ 6,105	$ 7,662	$ 17,270	$ 17,310
Proceeds from retained interests in securitization transactions	476	714	2,082	2,186
CLOs | Special Purpose Entities
Variable Interest Entity [Line Items]
Proceeds from sale of corporate loans sold to those SPEs	$ 121	$ 447	$ 1,086	$ 1,572