Derivative Instruments - Notional Amount of Derivative Contracts (Details) - USD ($) $ in Billions	Dec. 31, 2015	Dec. 31, 2014
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	$ 50,659	$ 63,662
Interest rate contracts
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	36,731	48,085
Interest rate swaps
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	24,162	29,734
Interest rate futures and forwards
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	5,167	10,189
Interest rate options | Written options
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	3,506	3,903
Interest rate options | Purchased options
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	3,896	4,259
Credit derivatives
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	2,900	4,249
Foreign exchange contracts
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	9,623	9,585
Foreign exchange cross-currency swaps
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	3,199	3,346
Foreign exchange spot, futures and forwards
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	5,028	4,669
Foreign exchange options | Written options
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	690	790
Foreign exchange options | Purchased options
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	706	780
Equity contracts
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	996	1,063
Equity swaps
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	232	206
Equity futures and forwards
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	43	50
Equity options | Written options
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	395	432
Equity options | Purchased options
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	326	375
Commodity contracts
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	409	680
Commodity swaps
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	83	126
Commodity spot, futures and forwards
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	99	193
Commodity options | Written options
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	115	181
Commodity options | Purchased options
Notional amount of derivative contracts outstanding [Abstract]
Derivative notional amounts	$ 112	$ 180