Derivative Instruments - Notional Amount of Derivative Contracts (Details) - USD ($) $ in Billions	Mar. 31, 2016	Dec. 31, 2015
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	$ 53,090	$ 50,659
Interest rate contracts
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	37,749	36,731
Interest rate swaps
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	25,334	24,162
Interest rate futures and forwards
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	5,355	5,167
Interest rate options | Written options
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	3,355	3,506
Interest rate options | Purchased options
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	3,705	3,896
Credit derivatives
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	3,137	2,900
Foreign exchange contracts
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	10,653	9,623
Foreign exchange cross-currency swaps
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	3,360	3,199
Foreign exchange spot, futures and forwards
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	5,677	5,028
Foreign exchange options | Written options
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	813	690
Foreign exchange options | Purchased options
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	803	706
Equity contracts
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	1,111	996
Equity swaps
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	246	232
Equity futures and forwards
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	42	43
Equity options | Written options
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	447	395
Equity options | Purchased options
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	376	326
Commodity contracts
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	440	409
Commodity swaps
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	80	83
Commodity spot, futures and forwards
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	115	99
Commodity options | Written options
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	124	115
Commodity options | Purchased options
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	$ 121	$ 112