Loans (Narrative) (Detail) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021	Sep. 30, 2021
Loans [Line Items]
Loans, net of unearned income	$ 38,167,613	$ 34,789,104	$ 33,264,043
Net deferred loan fees and costs and fair value accounting adjustments	73,100	50,800	13,100
Net deferred loan fees and costs and fair value accounting adjustments, paid by SBA under PPP	1,700
Commercial
Loans [Line Items]
Loans, net of unearned income	12,259,250	11,904,068	11,187,972
Commercial \| Commercial PPP loans
Loans [Line Items]
Loans, net of unearned income	43,658	558,283	1,081,988
Premium finance receivables
Loans [Line Items]
Unearned income portion of premium finance receivables	$ 180,100	$ 135,500	$ 124,000

Amount of fee received for commitment to originate or purchase financing receivable where likelihood of commitment being exercised is remote, to be recognized as service income.

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-Publisher FASB
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Amortized cost excluding accrued interest, before allowance for credit loss, of financing receivable. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Amount of unamortized loan commitment, origination, and other costs (fees) and purchase premium (discount) on financing receivable recognized as adjustment to yield. Excludes financing receivable covered under loss sharing agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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Loans [Line Items]

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Unamortized Loan Commitment And Origination Fees And Unamortized Discounts Or Premiums, Paid By Small Business Administration Under Paycheck Protection Program

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