Interest Income and Interest Expense - Interest Income and Interest Expense (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Interest income and expense
Deposits with banks	$ 205	$ 377
Collateralized agreements	534	1,304
Trading assets	1,573	1,388
Investments	471	395
Loans	1,316	1,319
Other interest	651	814
Total interest income	4,750	5,597
Deposits	818	857
Collateralized financings	448	669
Trading liabilities	314	366
Short-term borrowings	141	142
Long-term borrowings	1,105	1,384
Other interest	611	961
Total interest expense	3,437	4,379
Net interest income	$ 1,313	$ 1,218