Offsetting Arrangements - Liabilities With Offsetting Arrangements (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Offsetting Liabilities [Line Items]
Gross amounts of recognized liabilities	$ 8,240	$ 11,153
Gross amounts offset in statement of condition	(4,678)	(7,021)
Derivative collateral, cash offset	(731)	(1,118)
Net Amounts of Liabilities Presented in Statement of Condition	3,562	4,132
Gross amounts of recognized liabilities	46,363	46,766
Gross amounts offset in statement of condition	(36,580)	(38,997)
Net Amounts of Liabilities Presented in Statement of Condition	9,783	7,769
Gross amounts of recognized liabilities	54,603	57,919
Gross amounts offset in statement of condition	(41,258)	(46,018)
Total, net amount of liabilities presented in statement of condition	13,345	11,901
Securities sold under repurchase agreements	4,364	4,499
Securities lending, fair value, amount not offset against collateral	5,419	3,270
Foreign exchange contracts
Offsetting Liabilities [Line Items]
Gross amounts of recognized liabilities	7,901	10,868
Gross amounts offset in statement of condition	(3,936)	(5,896)
Net Amounts of Liabilities Presented in Statement of Condition	3,965	4,972
Interest-rate contracts
Offsetting Liabilities [Line Items]
Gross amounts of recognized liabilities	189	182
Gross amounts offset in statement of condition	(8)	(5)
Net Amounts of Liabilities Presented in Statement of Condition	181	177
Other derivative contracts
Offsetting Liabilities [Line Items]
Gross amounts of recognized liabilities	150	103
Gross amounts offset in statement of condition	(3)	(2)
Net Amounts of Liabilities Presented in Statement of Condition	$ 147	$ 101