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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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Fair Values of Assets and Liabilities - Estimated Fair Values of Financial Instruments (Detail) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financial Assets
Cash and due from banks	$ 21,453	$ 19,505	$ 15,705	$ 11,147
Investment securities held-to-maturity	46,050	44,362
Loans	282,837	276,507
Financial Liabilities
Time deposits	44,554	33,356
Long-term debt	41,340	32,259
Carrying Amount [Member]
Financial Assets
Cash and due from banks	21,453	19,505
Federal funds sold and securities purchased under resale agreements	306	93
Investment securities held-to-maturity	46,050	44,362
Loans held for sale	21	20
Loans	282,837	276,507
Other	2,412	2,393
Financial Liabilities
Time deposits	44,554	33,356
Short-term borrowings	12,921	15,656
Long-term debt	41,340	32,259
Other	1,726	1,556
Fair Value [Member]
Financial Assets
Cash and due from banks	21,453	19,505
Federal funds sold and securities purchased under resale agreements	306	93
Investment securities held-to-maturity	44,964	43,723
Loans held for sale	21	20
Loans	284,790	279,391
Other	2,412	2,401
Financial Liabilities
Time deposits	44,140	33,120
Short-term borrowings	12,678	15,447
Long-term debt	41,003	32,377
Other	1,726	1,556
Fair Value [Member] \| Level 1 [Member]
Financial Assets
Cash and due from banks	21,453	19,505
Investment securities held-to-maturity	4,594	4,613
Fair Value [Member] \| Level 2 [Member]
Financial Assets
Federal funds sold and securities purchased under resale agreements	306	93
Investment securities held-to-maturity	40,359	39,095
Other	1,241	1,037
Financial Liabilities
Time deposits	44,140	33,120
Short-term borrowings	12,678	15,447
Long-term debt	41,003	32,377
Fair Value [Member] \| Level 3 [Member]
Financial Assets
Investment securities held-to-maturity	11	15
Loans held for sale	21	20
Loans	284,790	279,391
Other	1,171	1,364
Financial Liabilities
Other	$ 1,726	$ 1,556