Offsetting Arrangements - Liabilities With Offsetting Arrangements (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Offsetting Liabilities [Line Items]
Derivatives, Gross amounts of recognized liabilities	$ 16,684	$ 11,153
Derivatives, Gross amounts offset in statement of condition	(10,682)	(7,021)
Derivatives, Net Amounts of Liabilities Presented in Statement of Condition	6,002	4,132
Derivative, Net Amount	5,822	4,068
Derivatives, Cash and collateral securities netting, offset	2,356	1,118
Derivatives, Cash and collateral securities netting, Cash and Securities Provided	180	64
Derivatives, Cash and collateral securities netting, Net	(2,536)	(1,182)
Resale agreements and securities lending, Gross Amounts of Recognized Liabilities(1)(2)	44,933	46,766
Resale agreements and securities lending, Gross Amounts Offset in Statement of Condition(3)	(35,517)	(38,997)
Resale agreements and securities lending, Net Amounts of Liabilities Presented in Statement of Condition	9,416	7,769
Resale agreements and securities lending, Cash and Securities Provided	(7,059)	(5,350)
Resale agreements and securities lending, Net Amount	2,357	2,419
Total derivatives and other financial instruments, Gross Amounts of Recognized Liabilities	61,617	57,919
Total derivatives and other financial instruments, Gross Amounts Offset in Statement of Condition	(46,199)	(46,018)
Total derivatives and other financial instruments, Net Amounts of Liabilities Presented in Statement of Condition	15,418	11,901
Total derivatives and other financial instruments, Cash and Securities Provided	(7,239)	(5,414)
Total derivatives and other financial instruments, Net Amount	8,179	6,487
Securities sold under repurchase agreements	4,400	4,499
Securities lending, fair value, amount not offset against collateral	5,016	3,270
Foreign exchange contracts
Offsetting Liabilities [Line Items]
Derivatives, Gross amounts of recognized liabilities	15,956	10,868
Derivatives, Gross amounts offset in statement of condition	(8,253)	(5,896)
Derivatives, Net Amounts of Liabilities Presented in Statement of Condition	7,703	4,972
Derivative, Net Amount	7,703	4,972
Interest-rate contracts
Offsetting Liabilities [Line Items]
Derivatives, Gross amounts of recognized liabilities	348	182
Derivatives, Gross amounts offset in statement of condition	(73)	(5)
Derivatives, Net Amounts of Liabilities Presented in Statement of Condition	275	177
Derivative, Net Amount	275	177
Other derivative contracts
Offsetting Liabilities [Line Items]
Derivatives, Gross amounts of recognized liabilities	380	103
Derivatives, Gross amounts offset in statement of condition	0	(2)
Derivatives, Net Amounts of Liabilities Presented in Statement of Condition	380	101
Derivative, Net Amount	$ 380	$ 101