For banks and other depository institutions: Includes cash on hand (currency and coin), cash items in process of collection, noninterest bearing deposits due from other financial institutions (including corporate credit unions), and noninterest bearing balances with the Federal Reserve Banks, Federal Home Loan Banks and central banks.

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Fair Values of Assets and Liabilities - Estimated Fair Values of Financial Instruments (Detail) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2018
Financial Assets
Cash and due from banks	$ 52,392	$ 22,405	$ 16,932	$ 21,453
Loans	302,952	292,082
Financial Liabilities
Long-term debt	42,579	40,167
Carrying Amount [Member]
Financial Assets
Cash and due from banks	52,392	22,405
Federal funds sold and securities purchased under resale agreements	395	1,036
Loans held for sale	94	45
Loans	302,952	292,082
Other	1,991	1,923
Financial Liabilities
Time deposits	38,300	42,894
Short-term borrowings	18,835	22,095
Long-term debt	42,579	40,167
Other	3,481	3,678
Fair Value [Member]
Financial Assets
Cash and due from banks	52,392	22,405
Federal funds sold and securities purchased under resale agreements	395	1,036
Loans held for sale	94	43
Loans	315,519	297,241
Other	1,991	1,923
Financial Liabilities
Time deposits	38,387	42,831
Short-term borrowings	18,738	21,961
Long-term debt	43,728	41,077
Other	3,481	3,678
Fair Value [Member] \| Level 1 [Member]
Financial Assets
Cash and due from banks	52,392	22,405
Fair Value [Member] \| Level 2 [Member]
Financial Assets
Federal funds sold and securities purchased under resale agreements	395	1,036
Other	1,128	929
Financial Liabilities
Time deposits	38,387	42,831
Short-term borrowings	18,738	21,961
Long-term debt	43,728	41,077
Other	1,280	1,342
Fair Value [Member] \| Level 3 [Member]
Financial Assets
Loans held for sale	94	43
Loans	315,519	297,241
Other	863	994
Financial Liabilities
Other	$ 2,201	$ 2,336