Commitments and Guarantees - Contractual Amounts of Credit-Related Off-Balance Sheet Financial Instruments (Details) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Indemnified securities financing	$ 337,941	$ 320,436
Stable value protection	24,771	24,583
Asset purchase agreements	4,128	3,990
Standby letters of credit	$ 4,293	$ 4,700