Derivative Instruments (Details) (USD $) In Billions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Notional amount of derivative contracts outstanding [Abstract]
Total derivative notional amounts	$ 69,550.0	$ 71,156.0
Interest Rate Contract [Member]
Notional amount of derivative contracts outstanding [Abstract]
Total derivative notional amounts	52,784.0	54,460.0
Credit derivatives
Notional amount of derivative contracts outstanding [Abstract]
Total derivative notional amounts	5,981.0	5,774.0
Foreign exchange
Notional amount of derivative contracts outstanding [Abstract]
Total derivative notional amounts	8,700.0	8,787.0
Equity
Notional amount of derivative contracts outstanding [Abstract]
Total derivative notional amounts	1,057.0	1,022.0
Commodity
Notional amount of derivative contracts outstanding [Abstract]
Total derivative notional amounts	1,028.0	1,113.0
Swap [Member] | Interest Rate Contract [Member]
Notional amount of derivative contracts outstanding [Abstract]
Total derivative notional amounts	33,183.0	38,704.0
Swap [Member] | Equity
Notional amount of derivative contracts outstanding [Abstract]
Total derivative notional amounts	163.0	119.0
Swap [Member] | Commodity
Notional amount of derivative contracts outstanding [Abstract]
Total derivative notional amounts	313.0	341.0
Future and forwards [Member] | Interest Rate Contract [Member]
Notional amount of derivative contracts outstanding [Abstract]
Total derivative notional amounts	11,824.0	7,888.0
Future and forwards [Member] | Equity
Notional amount of derivative contracts outstanding [Abstract]
Total derivative notional amounts	49.0	38.0
Written options [Member] | Interest Rate Contract [Member]
Notional amount of derivative contracts outstanding [Abstract]
Total derivative notional amounts	3,866.0	3,842.0
Written options [Member] | Foreign exchange
Notional amount of derivative contracts outstanding [Abstract]
Total derivative notional amounts	651.0	674.0
Written options [Member] | Equity
Notional amount of derivative contracts outstanding [Abstract]
Total derivative notional amounts	442.0	460.0
Written options [Member] | Commodity
Notional amount of derivative contracts outstanding [Abstract]
Total derivative notional amounts	265.0	310.0
Purchased options [Member] | Interest Rate Contract [Member]
Notional amount of derivative contracts outstanding [Abstract]
Total derivative notional amounts	3,911.0	4,026.0
Purchased options [Member] | Foreign exchange
Notional amount of derivative contracts outstanding [Abstract]
Total derivative notional amounts	661.0	670.0
Purchased options [Member] | Equity
Notional amount of derivative contracts outstanding [Abstract]
Total derivative notional amounts	403.0	405.0
Purchased options [Member] | Commodity
Notional amount of derivative contracts outstanding [Abstract]
Total derivative notional amounts	260.0	274.0
Cross-currency swaps [Member] | Foreign exchange
Notional amount of derivative contracts outstanding [Abstract]
Total derivative notional amounts	3,355.0	2,931.0
Spot futures and forwards [Member] | Foreign exchange
Notional amount of derivative contracts outstanding [Abstract]
Total derivative notional amounts	4,033.0	4,512.0
Spot futures and forwards [Member] | Commodity
Notional amount of derivative contracts outstanding [Abstract]
Total derivative notional amounts	190.0	188.0
Chief Investment Office [Member] | Synthetic Credit Derivatives [Member] | Credit derivatives
Notional amount of derivative contracts outstanding [Abstract]
Total derivative notional amounts	$ 12.0