Trading Assets and Liabilities (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading assets	$ 21,092		$ 28,894
Trading liabilities	8,164		10,875
U.S. Treasury [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading assets	2,675		1,344
US Government agency issued or guaranteed [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading assets	3		19
US Government sponsored enterprises [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading assets	45	[1]	159	[1]
Obligations of U.S. states and political subdivision [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading assets	591		25
Asset backed securities [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading assets	481		481
Corporate and foreign bonds [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading assets	9,681		9,099
Other securities [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading assets	22		25
Precious metals [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading assets	1,992		11,751
Trading liabilities	22		3,826
Securities sold, not yet purchased [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading liabilities	683		308
Derivatives [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading assets	5,602		5,991
Derivatives [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading liabilities	7,459		6,741
Federal National Mortgage Association Certificates and Obligations (FNMA) [Member] | US Government sponsored enterprises [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading assets	45		133
Federal Home Loan Mortgage Corporation Certificates and Obligations (FHLMC) [Member] | US Government sponsored enterprises [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading assets	$ 0		$ 26

[1] Includes mortgage backed securities of $45 million and $133 million issued or guaranteed by the Federal National Mortgage Association ("FNMA") and $0 million and $26 million issued or guaranteed by the Federal Home Loan Mortgage Corporation ("FHLMC") at December 31, 2014 and 2013, respectively.