Trading Assets and Liabilities - Trading Assets and Liabilities (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014		Dec. 31, 2013
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading assets	$ 27,336		$ 28,894
Trading liabilities	9,349		10,875
U.S. Treasury [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading assets	2,140		1,344
US Government agency issued or guaranteed [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading assets	17		19
US Government sponsored enterprises [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading assets	64	[1]	159	[1]
Obligations of U.S. states and political subdivision [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading assets	25		25
Asset backed securities [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading assets	484		481
Corporate and foreign bonds [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading assets	10,265	[2]	9,099	[2]
Other securities [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading assets	21		25
Precious metals [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading assets	10,332		11,751
Trading liabilities	3,926		3,826
Derivatives [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading assets	3,988		5,991
Trading liabilities	4,989		6,741
Securities sold, not yet purchased [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading liabilities	$ 434		$ 308

[1] Includes mortgage backed securities of $38 million and $133 million issued or guaranteed by the Federal National Mortgage Association ("FNMA") and $26 million and $26 million issued or guaranteed by the Federal Home Loan Mortgage Corporation ("FHLMC") at March 31, 2014 and December 31, 2013, respectively.

[2] .