Commitments to originate real estate loans for sale.

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Commitments to sell real estate loans net.

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Interest rate swap agreements used for interest rate risk management.

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Amount before allowance of consumer installment revolving and home equity loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts.

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Other credit-related commitments.

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Other financial instruments.

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Amount of domestic interest-bearing checking and savings accounts, which may include money market accounts, NOW accounts, interest-bearing corporate checking accounts, brokered deposits and other savings accounts.

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Interest, dividends, rents, ancillary and other revenues earned but not yet received by the entity on its investments.

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Amount after offset of short term borrowing where a bank borrows, at the federal funds rate, from another bank and securities that an entity sells and agrees to repurchase at a specified date for a specified price.

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The amount outstanding of funds lent to other depository institutions, securities brokers, or securities dealers in the form of Federal Funds sold; for example, immediately available funds lent under agreements or contracts that mature in one business day or roll over under a continuing contract, regardless of the nature of the transaction or the collateral involved, excluding overnight lending for commercial and industrial purposes. Also include Federal Funds sold under agreements to resell on a gross basis, excluding (1) sales of term Federal Funds, (2) due bills representing purchases of securities or other assets by the reporting bank that have not yet been delivered and similar instruments, (3) resale agreements that mature in more than one business day involving assets other than securities, and (4) yield maintenance dollar repurchase agreements.

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For banks and other depository institutions (including Federal Reserve Banks, if applicable): Interest-bearing deposits in other financial institutions for relatively short periods of time including, for example, certificates of deposits, which are presented separately from cash on the balance sheet.

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Sum of the carrying amounts as of the balance sheet date of all investments.

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Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements and loans held for sale.

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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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Amount of domestic noninterest-bearing deposits held by the entity, which may include demand deposits, checking, brokered and retail deposits.

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Amount, before allowance for credit loss, of financing receivable.

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Amount of time deposit liabilities, including certificates of deposit.

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Amount of investment in debt security measured at fair value with change in fair value recognized in net income (trading) and investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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Fair Value Measurements - Carrying Amounts and Estimated Fair Value for Financial Instrument Assets (Liabilities) (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Financial assets:
Interest-bearing deposits at banks	$ 7,190,154	$ 8,105,197
Federal funds sold	3,500
Investment securities	9,497,251	12,692,813
Loans and leases:
Commercial loans and leases	89,776,328	87,326,591
Allowance for credit losses	(1,051,071)	(1,019,444)	$ (1,017,198)	$ (988,997)
Loans and leases, net	89,871,798	87,447,033
Financial liabilities:
Noninterest-bearing deposits	(32,396,407)	(32,256,668)
Savings and interest-checking deposits	(54,932,162)	(50,963,744)
Time deposits	(5,757,456)	(6,124,254)
Deposits at Cayman Islands office	(1,684,044)	(811,906)
Long-term borrowings	(6,986,186)	(8,444,914)
Carrying Amount [Member]
Financial assets:
Cash and cash equivalents	1,432,805	1,605,439
Interest-bearing deposits at banks	7,190,154	8,105,197
Federal funds sold	3,500
Trading account assets	470,129	185,584
Investment securities	9,497,251	12,692,813
Loans and leases:
Consumer loans	15,386,693	13,970,499
Allowance for credit losses	(1,051,071)	(1,019,444)
Loans and leases, net	89,871,798	87,447,033
Accrued interest receivable	333,142	353,965
Financial liabilities:
Noninterest-bearing deposits	(32,396,407)	(32,256,668)
Savings and interest-checking deposits	(54,932,162)	(50,963,744)
Time deposits	(5,757,456)	(6,124,254)
Deposits at Cayman Islands office	(1,684,044)	(811,906)
Short-term borrowings	(62,363)	(4,398,378)
Long-term borrowings	(6,986,186)	(8,444,914)
Accrued interest payable	(105,374)	(95,274)
Trading account liabilities	(79,903)	(178,125)
Other financial instruments:
Commitments to originate real estate loans for sale	10,740	7,712
Commitments to sell real estate loans	300	(6,177)
Other credit-related commitments	(136,470)	(131,688)
Interest rate swap agreements used for interest rate risk management	(1,762)	5,530
Estimate Fair Value [Member]
Financial assets:
Cash and cash equivalents	1,432,805	1,605,439
Interest-bearing deposits at banks	7,190,154	8,105,197
Federal funds sold	3,500
Trading account assets	470,129	185,584
Investment securities	9,539,540	12,631,656
Loans and leases:
Consumer loans	15,413,262	13,819,545
Loans and leases, net	90,668,624	87,214,035
Accrued interest receivable	333,142	353,965
Financial liabilities:
Noninterest-bearing deposits	(32,396,407)	(32,256,668)
Savings and interest-checking deposits	(54,932,162)	(50,963,744)
Time deposits	(5,829,347)	(6,201,957)
Deposits at Cayman Islands office	(1,684,044)	(811,906)
Short-term borrowings	(62,363)	(4,398,378)
Long-term borrowings	(7,063,165)	(8,385,289)
Accrued interest payable	(105,374)	(95,274)
Trading account liabilities	(79,903)	(178,125)
Other financial instruments:
Commitments to originate real estate loans for sale	10,740	7,712
Commitments to sell real estate loans	300	(6,177)
Other credit-related commitments	(136,470)	(131,688)
Interest rate swap agreements used for interest rate risk management	(1,762)	5,530
Estimate Fair Value [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Financial assets:
Cash and cash equivalents	1,394,984	1,528,302
Trading account assets	49,040	46,018
Investment securities	100,637	71,989
Estimate Fair Value [Member] \| Significant Observable Inputs (Level 2) [Member]
Financial assets:
Cash and cash equivalents	37,821	77,137
Interest-bearing deposits at banks	7,190,154	8,105,197
Federal funds sold	3,500
Trading account assets	421,089	139,566
Investment securities	9,351,793	12,456,467
Loans and leases:
Loans and leases, net	4,019,186	4,267,222
Accrued interest receivable	333,142	353,965
Financial liabilities:
Noninterest-bearing deposits	(32,396,407)	(32,256,668)
Savings and interest-checking deposits	(54,932,162)	(50,963,744)
Time deposits	(5,829,347)	(6,201,957)
Deposits at Cayman Islands office	(1,684,044)	(811,906)
Short-term borrowings	(62,363)	(4,398,378)
Long-term borrowings	(7,063,165)	(8,385,289)
Accrued interest payable	(105,374)	(95,274)
Trading account liabilities	(79,903)	(178,125)
Other financial instruments:
Commitments to sell real estate loans	300	(6,177)
Interest rate swap agreements used for interest rate risk management	(1,762)	5,530
Estimate Fair Value [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Financial assets:
Investment securities	87,110	103,200
Loans and leases:
Consumer loans	15,413,262	13,819,545
Loans and leases, net	86,649,438	82,946,813
Other financial instruments:
Commitments to originate real estate loans for sale	10,740	7,712
Other credit-related commitments	(136,470)	(131,688)
Commercial Loans and Leases [Member] \| Carrying Amount [Member]
Loans and leases:
Commercial loans and leases	23,838,168	22,977,976
Commercial Loans and Leases [Member] \| Estimate Fair Value [Member]
Loans and leases:
Commercial loans and leases	23,510,908	22,587,387
Commercial Loans and Leases [Member] \| Estimate Fair Value [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Loans and leases:
Commercial loans and leases	23,510,908	22,587,387
Commercial [Member] \| Carrying Amount [Member]
Loans and leases:
Commercial loans and leases	35,541,914	34,363,556
Commercial [Member] \| Estimate Fair Value [Member]
Loans and leases:
Commercial loans and leases	35,517,180	33,832,558
Commercial [Member] \| Estimate Fair Value [Member] \| Significant Observable Inputs (Level 2) [Member]
Loans and leases:
Commercial loans and leases	28,338	346,775
Commercial [Member] \| Estimate Fair Value [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Loans and leases:
Commercial loans and leases	35,488,842	33,485,783
Residential Real Estate Loans \| Carrying Amount [Member]
Loans and leases:
Commercial loans and leases	16,156,094	17,154,446
Residential Real Estate Loans \| Estimate Fair Value [Member]
Loans and leases:
Commercial loans and leases	16,227,274	16,974,545
Residential Real Estate Loans \| Estimate Fair Value [Member] \| Significant Observable Inputs (Level 2) [Member]
Loans and leases:
Commercial loans and leases	3,990,848	3,920,447
Residential Real Estate Loans \| Estimate Fair Value [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Loans and leases:
Commercial loans and leases	$ 12,236,426	$ 13,054,098