Loans and Other Real Estate - Composition of Loan and Lease Portfolio (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 5,769,127	$ 5,140,940
Less: deferred fees	(12,972)	(3,117)
Loans, net of deferred fees	5,756,155	5,137,823
Commercial, secured by real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	3,961,476	3,589,593
Commercial, industrial and other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	402,239	431,934
Paycheck Protection Program ("PPP")
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	325,999	0
Equipment finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	115,651	111,076
Real estate - residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	334,455	335,191
Real estate - construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	299,441	335,169
Home equity and consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 329,866	$ 337,977