Variable Interest Entities and Securitization Activities (Narrative) (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Variable Interest Entity
Nonredeemable noncontrolling interests	$ 1,133	$ 1,204
Additional maximum exposure to losses	69	105
Securities issued by SPEs	13,700	14,000
Managed Real Estate Partnerships
Variable Interest Entity
Nonredeemable noncontrolling interests	$ 59	$ 240