Commitments and Guarantees - Contractual Amounts of Credit-Related Off-Balance Sheet Financial Instruments (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Indemnified securities financing	$ 330,821	$ 349,766
Stable value protection	23,588	23,409
Asset purchase agreements	4,322	4,107
Standby letters of credit	$ 4,769	$ 4,720