Offsetting Arrangements - Liabilities With Offsetting Arrangements (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Offsetting Liabilities [Line Items]
Gross Amounts of Recognized Liabilities	$ 10,329	$ 15,234
Gross Amounts Offset in Statement of Condition	(5,963)	(8,926)
Net Amounts of Liabilities Presented in Statement of Condition	4,366	6,308
Derivative Collateral, Cash Offset	(1,241)	(2,630)
Total Net Derivative Liability	4,366	6,308
Gross Amounts of Recognized Liabilities	49,223	44,562
Gross Amounts Offset in Statement of Condition	(33,810)	(29,157)
Net Amounts of Liabilities Presented in Statement of Condition	15,413	15,405
Gross Amounts of Recognized Liabilities	59,552	59,796
Gross Amounts Offset in Statement of Condition	(39,773)	(38,083)
Total, Net Amount of Liabilities Presented in Statement of Condition	19,779	21,713
Securities sold under repurchase agreements	10,978	8,925
Securities Lending, Fair Value, Amount Not Offset Against Collateral	4,435	6,480
Foreign exchange contracts
Offsetting Liabilities [Line Items]
Gross Amounts of Recognized Liabilities	10,003	14,925
Gross Amounts Offset in Statement of Condition	(4,698)	(6,275)
Net Amounts of Liabilities Presented in Statement of Condition	5,305	8,650
Interest-rate contracts
Offsetting Liabilities [Line Items]
Gross Amounts of Recognized Liabilities	219	239
Gross Amounts Offset in Statement of Condition	(21)	(20)
Net Amounts of Liabilities Presented in Statement of Condition	198	219
Equity Derivative Contracts
Offsetting Liabilities [Line Items]
Gross Amounts of Recognized Liabilities	1	0
Gross Amounts Offset in Statement of Condition	(1)	0
Net Amounts of Liabilities Presented in Statement of Condition	0	0
Other Derivative Contracts
Offsetting Liabilities [Line Items]
Gross Amounts of Recognized Liabilities	106	70
Gross Amounts Offset in Statement of Condition	(2)	(1)
Net Amounts of Liabilities Presented in Statement of Condition	$ 104	$ 69