Loans and Leases and Allowance for Credit Losses - Recorded investment in nonaccrual loans by loan class (Details) - Loans receivable - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Financing Receivable, Recorded Investment, Aging [Abstract]
Nonaccrual loans with no allowance	$ 14,801
Nonaccrual loans with an allowance	21,407
Nonaccrual loans	36,208	$ 35,341
Commercial
Financing Receivable, Recorded Investment, Aging [Abstract]
Nonaccrual loans with no allowance	10,538
Nonaccrual loans with an allowance	9,434
Nonaccrual loans	19,972	20,503
Commercial | Owner occupied commercial real estate
Financing Receivable, Recorded Investment, Aging [Abstract]
Nonaccrual loans with no allowance	6,889
Nonaccrual loans with an allowance	3,516
Nonaccrual loans	10,405	10,544
Commercial | Income producing commercial real estate
Financing Receivable, Recorded Investment, Aging [Abstract]
Nonaccrual loans with no allowance	1,039
Nonaccrual loans with an allowance	1,196
Nonaccrual loans	2,235	1,996
Commercial | Commercial & industrial
Financing Receivable, Recorded Investment, Aging [Abstract]
Nonaccrual loans with no allowance	1,332
Nonaccrual loans with an allowance	1,837
Nonaccrual loans	3,169	2,545
Commercial | Construction
Financing Receivable, Recorded Investment, Aging [Abstract]
Nonaccrual loans with no allowance	1,235
Nonaccrual loans with an allowance	489
Nonaccrual loans	1,724	2,277
Commercial | Equipment financing
Financing Receivable, Recorded Investment, Aging [Abstract]
Nonaccrual loans with no allowance	43
Nonaccrual loans with an allowance	2,396
Nonaccrual loans	2,439	3,141
Residential | Residential mortgage
Financing Receivable, Recorded Investment, Aging [Abstract]
Nonaccrual loans with no allowance	3,163
Nonaccrual loans with an allowance	9,295
Nonaccrual loans	12,458	10,567
Residential | Home equity lines of credit
Financing Receivable, Recorded Investment, Aging [Abstract]
Nonaccrual loans with no allowance	962
Nonaccrual loans with an allowance	2,048
Nonaccrual loans	3,010	3,173
Residential | Construction
Financing Receivable, Recorded Investment, Aging [Abstract]
Nonaccrual loans with no allowance	130
Nonaccrual loans with an allowance	410
Nonaccrual loans	540	939
Consumer
Financing Receivable, Recorded Investment, Aging [Abstract]
Nonaccrual loans with no allowance	8
Nonaccrual loans with an allowance	220
Nonaccrual loans	$ 228	$ 159