Derivative Instruments - Notional Amount of Derivative Contracts (Details) - USD ($) $ in Billions	Dec. 31, 2016	Dec. 31, 2015
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	$ 47,537	$ 50,659
Interest rate contracts
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	33,862	36,731
Interest rate swaps
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	22,000	24,162
Interest rate futures and forwards
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	5,289	5,167
Interest rate options | Written options
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	3,091	3,506
Interest rate options | Purchased options
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	3,482	3,896
Credit derivatives
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	2,032	2,900
Foreign exchange contracts
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	10,155	9,623
Foreign exchange cross-currency swaps
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	3,359	3,199
Foreign exchange spot, futures and forwards
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	5,341	5,028
Foreign exchange options | Written options
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	734	690
Foreign exchange options | Purchased options
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	721	706
Equity contracts
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	1,079	996
Equity swaps
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	258	232
Equity futures and forwards
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	59	43
Equity options | Written options
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	417	395
Equity options | Purchased options
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	345	326
Commodity contracts
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	409	409
Commodity swaps
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	102	83
Commodity spot, futures and forwards
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	130	99
Commodity options | Written options
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	83	115
Commodity options | Purchased options
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	$ 94	$ 112