Commitments and Guarantees - Contractual Amounts of Credit-Related Off-Balance Sheet Financial Instruments (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Indemnified securities financing	$ 344,257	$ 320,436
Stable value protection	26,071	24,583
Asset purchase agreements	4,405	3,990
Standby letters of credit	$ 4,159	$ 4,700