Amount, after troubled debt restructuring, of modified financing receivable.

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Loans and Leases - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Financing Receivable, Recorded Investment [Line Items]
Outstanding loans to Executive officers, directors, principal shareholders, related interest and parties	$ 38,100		$ 38,200
Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Delinquent loans selectively extended to certain borrowers, rate reductions, forbearance of arrears, and extension of maturity dates	1,572	$ 3,088
Loan classified as non accrual TDRs	566,000
Commercial And Industrial Sector And One To Four Family Mortgage Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan classified as non accrual TDRs	600,000		$ 140,000
Financing Receivable Troubled Debt Restructurings Rate Reductions
Financing Receivable, Recorded Investment [Line Items]
Delinquent loans selectively extended to certain borrowers, rate reductions, forbearance of arrears, and extension of maturity dates	25,400
Financing Receivable Troubled Debt Restructurings Forbearance of Arrears
Financing Receivable, Recorded Investment [Line Items]
Delinquent loans selectively extended to certain borrowers, rate reductions, forbearance of arrears, and extension of maturity dates	$ 4,200