Allowance for Loan and Lease Losses and Reserve for Unfunded Commitments - Summary of Recorded Investment, Unpaid Principal Balance, and Related Allowance for Loans and Leases Considered Impaired (Details) - Loans Excluding Acquired Impaired Loans - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Financing Receivable Impaired [Line Items]
Recorded Investment	$ 77,890	$ 68,741
Unpaid Principal Balance	84,163	75,668
Related Allowance	14,782	10,690
Commercial Real Estate
Financing Receivable Impaired [Line Items]
Recorded Investment, With no related allowance recorded	26,129	16,556
Recorded Investment, With an allowance recorded	12,872	9,840
Unpaid Principal Balance, With no related allowance recorded	27,378	19,808
Unpaid Principal Balance, With an allowance recorded	14,624	10,691
Related Allowance	4,516	2,614
Residential Real Estate
Financing Receivable Impaired [Line Items]
Recorded Investment, With no related allowance recorded	1,364	2,165
Recorded Investment, With an allowance recorded	272	233
Unpaid Principal Balance, With no related allowance recorded	1,451	2,253
Unpaid Principal Balance, With an allowance recorded	274	233
Related Allowance	77	124
Construction, Land Development, and Other Land
Financing Receivable Impaired [Line Items]
Recorded Investment, With no related allowance recorded		2,644
Unpaid Principal Balance, With no related allowance recorded		3,000
Commercial and Industrial
Financing Receivable Impaired [Line Items]
Recorded Investment, With no related allowance recorded	19,010	19,211
Recorded Investment, With an allowance recorded	18,243	18,092
Unpaid Principal Balance, With no related allowance recorded	20,698	20,398
Unpaid Principal Balance, With an allowance recorded	19,738	19,285
Related Allowance	$ 10,189	$ 7,952