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	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Financial Assets
Cash and due from banks	$ 22,405	$ 21,453	$ 19,505	$ 15,705
Investment securities held-to-maturity		46,050
Loans	292,082	282,837
Financial Liabilities
Time deposits	42,894	44,554
Long-term debt	40,167	41,340
Carrying Amount [Member]
Financial Assets
Cash and due from banks	22,405	21,453
Federal funds sold and securities purchased under resale agreements	1,036	306
Investment securities held-to-maturity		46,050
Loans held for sale	45	21
Loans	292,082	282,837
Other	1,923	2,412
Financial Liabilities
Time deposits	42,894	44,554
Short-term borrowings	22,095	12,921
Long-term debt	40,167	41,340
Other	3,678	1,726
Fair Value [Member]
Financial Assets
Cash and due from banks	22,405	21,453
Federal funds sold and securities purchased under resale agreements	1,036	306
Investment securities held-to-maturity		44,964
Loans held for sale	43	21
Loans	297,241	284,790
Other	1,923	2,412
Financial Liabilities
Time deposits	42,831	44,140
Short-term borrowings	21,461	12,678
Long-term debt	41,077	41,003
Other	3,678	1,726
Fair Value [Member] \| Level 1 [Member]
Financial Assets
Cash and due from banks	22,405	21,453
Investment securities held-to-maturity		4,594
Fair Value [Member] \| Level 2 [Member]
Financial Assets
Federal funds sold and securities purchased under resale agreements	1,036	306
Investment securities held-to-maturity		40,359
Other	929	1,241
Financial Liabilities
Time deposits	42,831	44,140
Short-term borrowings	21,461	12,678
Long-term debt	41,077	41,003
Other	1,342
Fair Value [Member] \| Level 3 [Member]
Financial Assets
Investment securities held-to-maturity		11
Loans held for sale	43	21
Loans	297,241	284,790
Other	994	1,171
Financial Liabilities
Other	$ 2,336	$ 1,726