Loans and Leases and Allowance for Credit Losses - Recorded investment in nonaccrual loans by loan class (Details) - Loans receivable - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Financing Receivable, Recorded Investment, Aging [Abstract]
Nonaccrual loans with no allowance	$ 21,698
Nonaccrual loans with an allowance	27,386
Nonaccrual loans	49,084	$ 35,341
Commercial
Financing Receivable, Recorded Investment, Aging [Abstract]
Nonaccrual loans with no allowance	18,268
Nonaccrual loans with an allowance	13,571
Nonaccrual loans	31,839	20,503
Commercial | Owner occupied commercial real estate
Financing Receivable, Recorded Investment, Aging [Abstract]
Nonaccrual loans with no allowance	8,335
Nonaccrual loans with an allowance	2,740
Nonaccrual loans	11,075	10,544
Commercial | Income producing commercial real estate
Financing Receivable, Recorded Investment, Aging [Abstract]
Nonaccrual loans with no allowance	7,181
Nonaccrual loans with an allowance	5,049
Nonaccrual loans	12,230	1,996
Commercial | Commercial & industrial
Financing Receivable, Recorded Investment, Aging [Abstract]
Nonaccrual loans with no allowance	1,213
Nonaccrual loans with an allowance	2,321
Nonaccrual loans	3,534	2,545
Commercial | Construction
Financing Receivable, Recorded Investment, Aging [Abstract]
Nonaccrual loans with no allowance	1,428
Nonaccrual loans with an allowance	435
Nonaccrual loans	1,863	2,277
Commercial | Equipment financing
Financing Receivable, Recorded Investment, Aging [Abstract]
Nonaccrual loans with no allowance	111
Nonaccrual loans with an allowance	3,026
Nonaccrual loans	3,137	3,141
Residential | Residential mortgage
Financing Receivable, Recorded Investment, Aging [Abstract]
Nonaccrual loans with no allowance	1,964
Nonaccrual loans with an allowance	11,900
Nonaccrual loans	13,864	10,567
Residential | Home equity lines of credit
Financing Receivable, Recorded Investment, Aging [Abstract]
Nonaccrual loans with no allowance	1,066
Nonaccrual loans with an allowance	1,576
Nonaccrual loans	2,642	3,173
Residential | Construction
Financing Receivable, Recorded Investment, Aging [Abstract]
Nonaccrual loans with no allowance	181
Nonaccrual loans with an allowance	298
Nonaccrual loans	479	939
Consumer
Financing Receivable, Recorded Investment, Aging [Abstract]
Nonaccrual loans with no allowance	219
Nonaccrual loans with an allowance	41
Nonaccrual loans	$ 260	$ 159