Loans and Other Real Estate - Composition of Loan and Lease Portfolio (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 5,331,863	$ 5,140,940
Less: deferred fees	(3,240)	(3,117)
Loans, net of deferred fees	5,328,623	5,137,823
Commercial, secured by real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	3,740,319	3,589,593
Commercial, industrial and other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	467,346	431,934
Equipment finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	116,421	111,076
Real estate - residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	334,114	335,191
Real estate - construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	333,592	335,169
Home equity and consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 340,071	$ 337,977

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Amount of deferred interest and fee income, unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of acquired loans. Excludes amounts for loans and leases covered under loss sharing agreements.

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Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

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Amount before allowance and after 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.

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