Offsetting Arrangements - Liabilities With Offsetting Arrangements (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Offsetting Liabilities [Line Items]
Derivatives, Gross amounts of recognized liabilities	$ 11,844	$ 16,807
Derivatives, Gross amounts offset in statement of condition	(6,849)	(11,564)
Derivatives, Net Amounts of Liabilities Presented in Statement of Condition	4,995	5,243
Derivative, Net Amount	4,117	5,028
Derivative liability, collateral, cash offset	(547)	(1,341)
Derivatives, Cash and collateral securities netting, Cash and Securities Provided	(878)	(215)
Derivatives, Cash and collateral securities netting, Net	(1,425)	(1,556)
Resale agreements and securities lending, Gross Amounts of Recognized Liabilities(1)(2)	142,865	104,494
Resale agreements and securities lending, Gross Amounts Offset in Statement of Condition(3)	(127,744)	(91,889)
Resale agreements and securities lending, Net Amounts of Liabilities Presented in Statement of Condition	15,121	12,605
Resale agreements and securities lending, Cash and Securities Provided	(13,746)	(11,543)
Resale agreements and securities lending, Net Amount	1,375	1,062
Total derivatives and other financial instruments, Gross Amounts of Recognized Liabilities	154,709	121,301
Total derivatives and other financial instruments, Gross Amounts Offset in Statement of Condition	(134,593)	(103,453)
Total derivatives and other financial instruments, Net Amounts of Liabilities Presented in Statement of Condition	20,116	17,848
Total derivatives and other financial instruments, Cash and Securities Provided	(14,624)	(11,758)
Total derivatives and other financial instruments, Net Amount	5,492	6,090
Securities sold under repurchase agreements	1,829	1,082
Foreign exchange contracts
Offsetting Liabilities [Line Items]
Derivatives, Gross amounts of recognized liabilities	11,573	16,522
Derivatives, Gross amounts offset in statement of condition	(6,298)	(10,223)
Derivatives, Net Amounts of Liabilities Presented in Statement of Condition	5,275	6,299
Derivative, Net Amount	5,275	6,299
Interest rate contracts
Offsetting Liabilities [Line Items]
Derivatives, Gross amounts of recognized liabilities	54	71
Derivatives, Gross amounts offset in statement of condition	(4)	0
Derivatives, Net Amounts of Liabilities Presented in Statement of Condition	50	71
Derivative, Net Amount	50	71
Other derivative contracts
Offsetting Liabilities [Line Items]
Derivatives, Gross amounts of recognized liabilities	217	214
Derivatives, Gross amounts offset in statement of condition	0	0
Derivatives, Net Amounts of Liabilities Presented in Statement of Condition	217	214
Derivative, Net Amount	217	214
Accrued expenses and other liabilities
Offsetting Liabilities [Line Items]
Cash collateral received in connection to securities finance activities	$ 13,290	$ 11,520