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, 2019	Dec. 31, 2018
Financing Receivable Impaired [Line Items]
Recorded Investment	$ 53,176	$ 35,914
Unpaid Principal Balance	57,264	41,231
Related Allowance	9,562	6,649
Commercial Real Estate
Financing Receivable Impaired [Line Items]
Recorded Investment, With no related allowance recorded	15,636	6,110
Recorded Investment, With an allowance recorded	8,435	5,873
Unpaid Principal Balance, With no related allowance recorded	16,653	7,693
Unpaid Principal Balance, With an allowance recorded	9,246	6,313
Related Allowance	2,728	2,191
Residential Real Estate
Financing Receivable Impaired [Line Items]
Recorded Investment, With no related allowance recorded	2,246	1,886
Recorded Investment, With an allowance recorded	128	251
Unpaid Principal Balance, With no related allowance recorded	2,356	1,858
Unpaid Principal Balance, With an allowance recorded	146	253
Related Allowance	39	61
Commercial and Industrial
Financing Receivable Impaired [Line Items]
Recorded Investment, With no related allowance recorded	9,557	11,193
Recorded Investment, With an allowance recorded	17,174	10,601
Unpaid Principal Balance, With no related allowance recorded	10,510	13,961
Unpaid Principal Balance, With an allowance recorded	18,353	11,153
Related Allowance	$ 6,795	$ 4,397