Variable Interest Entities - Securitization Activity (Details 4) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Variable Interest Entity (VIE) or Potential VIE, Information Unavailability [Member] | Residential Mortgage [Member]
Securitization activity [Abstract]
Principal securitized	$ 0	$ 0	$ 0	$ 0
All cash flows during the period:
Proceeds from new securitizations	0	0	0	0
Servicing fees collected	155	164	506	576
Purchases of previously transferred financial assets (or the underlying collateral)	46	37	157	733
Cash flows received on the interests that continue to be held by the Firm	49	56	146	178
Variable Interest Entity (VIE) or Potential VIE, Information Unavailability [Member] | Commercial Mortgage Backed Securities [Member]
Securitization activity [Abstract]
Principal securitized	1,004	1,862	3,918	4,802
All cash flows during the period:
Proceeds from new securitizations	1,004	1,878	3,918	4,966
Servicing fees collected	1	1	3	3
Purchases of previously transferred financial assets (or the underlying collateral)	0	0	0	0
Cash flows received on the interests that continue to be held by the Firm	34	55	116	135
Fair Value, Inputs, Level 2 [Member] | Residential and commercial mortgage securitizations [Member]
All cash flows during the period:
Proceeds from new securitizations	1,000	1,200	3,900	3,800
Fair Value, Inputs, Level 3 [Member] | Residential and commercial mortgage securitizations [Member]
All cash flows during the period:
Proceeds from new securitizations		681		1,200
Third party co-sponsor [Member] | Variable Interest Entity (VIE) or Potential VIE, Information Unavailability [Member] | Commercial Mortgage Backed Securities [Member]
Securitization activity [Abstract]
Principal securitized			851
All cash flows during the period:
Proceeds from new securitizations			$ 859