Loans and Allowance for Credit Losses Allowance for Loan Losses by Portfolio Segment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	$ 272,920	$ 176,941	$ 166,209	$ 169,410
Loans charged off	5,489		27,539
Recoveries of loans previously charged off	7,847		14,660
Total net (charge-offs) recoveries	2,358		12,879
Provision for credit losses	7,080		70,680
Ending balance	282,358	172,797	282,358	172,797
Beginning balance		170,233	163,622	160,537
Loans charged off		(10,128)		(20,208)
Recovery of loans previously charged off		3,814		11,300
Net loans recovered (charged off)		(6,314)		(8,908)
Allowance for loan and lease losses, provision for loss, net of provision applied to unfunded commitments		2,216		14,506
Ending balance	266,825	166,135	266,825	166,135
Provision for Loan and Lease Losses	7,080	2,170	70,680	12,295
Financing Receivable, Allowance for Credit Losses
Accounts, Notes, Loans and Financing Receivable [Line Items]
Provision for Loan and Lease Losses	46,000		2,200
Real estate - commercial mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance		54,859		52,889
Loans charged off		(394)		(1,769)
Recovery of loans previously charged off		444		749
Net loans recovered (charged off)		50		(1,020)
Allowance for loan and lease losses, provision for loss, net of provision applied to unfunded commitments		(5,529)		(2,489)
Ending balance		49,380		49,380
Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance		66,341		58,868
Loans charged off		(7,181)		(11,863)
Recovery of loans previously charged off		2,311		6,234
Net loans recovered (charged off)		(4,870)		(5,629)
Allowance for loan and lease losses, provision for loss, net of provision applied to unfunded commitments		7,710		15,942
Ending balance		69,181		69,181
Real-estate - home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance		18,981		18,911
Loans charged off		(498)		(923)
Recovery of loans previously charged off		132		552
Net loans recovered (charged off)		(366)		(371)
Allowance for loan and lease losses, provision for loss, net of provision applied to unfunded commitments		(662)		(587)
Ending balance		17,953		17,953
Real estate - residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance		18,892		18,921
Loans charged off		(533)		(1,322)
Recovery of loans previously charged off		440		783
Net loans recovered (charged off)		(93)		(539)
Allowance for loan and lease losses, provision for loss, net of provision applied to unfunded commitments		(109)		308
Ending balance		18,690		18,690
Real-estate - construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance		4,928		5,061
Loans charged off		(45)		(143)
Recovery of loans previously charged off		164		1,493
Net loans recovered (charged off)		119		1,350
Allowance for loan and lease losses, provision for loss, net of provision applied to unfunded commitments		(664)		(2,028)
Ending balance		4,383		4,383
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance		3,363		3,217
Loans charged off		(877)		(2,355)
Recovery of loans previously charged off		216		1,005
Net loans recovered (charged off)		(661)		(1,350)
Allowance for loan and lease losses, provision for loss, net of provision applied to unfunded commitments		798		1,633
Ending balance		3,500		3,500
Equipment lease financing, other and overdrafts
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance		2,869		2,670
Loans charged off		(600)		(1,833)
Recovery of loans previously charged off		107		484
Net loans recovered (charged off)		(493)		(1,349)
Allowance for loan and lease losses, provision for loss, net of provision applied to unfunded commitments		672		1,727
Ending balance		$ 3,048		$ 3,048
Cumulative Effect, Period of Adoption, Adjustment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	0
Loans - Excluding OBS Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	256,537		163,622
Loans charged off	5,489		27,539
Recoveries of loans previously charged off	7,847		14,660
Total net (charge-offs) recoveries	2,358		12,879
Provision for credit losses	7,930		70,359
Ending balance	266,825		266,825
Loans - Excluding OBS Credit Exposure [Member] | Real estate - commercial mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	102,695		45,610
Loans charged off	746		3,925
Recoveries of loans previously charged off	100		439
Total net (charge-offs) recoveries	646		3,486
Provision for credit losses	9,806		40,370
Ending balance	111,855		111,855
Loans - Excluding OBS Credit Exposure [Member] | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	61,447		68,602
Loans charged off	2,969		17,348
Recoveries of loans previously charged off	2,103		6,815
Total net (charge-offs) recoveries	866		10,533
Provision for credit losses	(1,743)		19,345
Ending balance	58,838		58,838
Loans - Excluding OBS Credit Exposure [Member] | Real-estate - home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	16,391		17,744
Loans charged off	393		1,138
Recoveries of loans previously charged off	44		305
Total net (charge-offs) recoveries	349		833
Provision for credit losses	256		(548)
Ending balance	16,298		16,298
Loans - Excluding OBS Credit Exposure [Member] | Real estate - residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	46,443		19,771
Loans charged off	198		620
Recoveries of loans previously charged off	95		292
Total net (charge-offs) recoveries	103		328
Provision for credit losses	2,013		7,675
Ending balance	48,353		48,353
Loans - Excluding OBS Credit Exposure [Member] | Real-estate - construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	12,314		4,443
Loans charged off	0		17
Recoveries of loans previously charged off	4,873		4,943
Total net (charge-offs) recoveries	4,873		4,926
Provision for credit losses	(2,177)		1,626
Ending balance	15,010		15,010
Loans - Excluding OBS Credit Exposure [Member] | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	10,299		3,762
Loans charged off	701		2,788
Recoveries of loans previously charged off	447		1,481
Total net (charge-offs) recoveries	254		1,307
Provision for credit losses	260		1,881
Ending balance	10,305		10,305
Loans - Excluding OBS Credit Exposure [Member] | Equipment lease financing, other and overdrafts
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	6,948		3,690
Loans charged off	483		1,704
Recoveries of loans previously charged off	185		385
Total net (charge-offs) recoveries	298		1,319
Provision for credit losses	(484)		11
Ending balance	$ 6,166		6,166
Loans - Excluding OBS Credit Exposure [Member] | Cumulative Effect, Period of Adoption, Adjustment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance			45,723
Loans - Excluding OBS Credit Exposure [Member] | Cumulative Effect, Period of Adoption, Adjustment | Real estate - commercial mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance			29,361
Loans - Excluding OBS Credit Exposure [Member] | Cumulative Effect, Period of Adoption, Adjustment | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance			(18,576)
Loans - Excluding OBS Credit Exposure [Member] | Cumulative Effect, Period of Adoption, Adjustment | Real-estate - home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance			(65)
Loans - Excluding OBS Credit Exposure [Member] | Cumulative Effect, Period of Adoption, Adjustment | Real estate - residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance			21,235
Loans - Excluding OBS Credit Exposure [Member] | Cumulative Effect, Period of Adoption, Adjustment | Real-estate - construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance			4,015
Loans - Excluding OBS Credit Exposure [Member] | Cumulative Effect, Period of Adoption, Adjustment | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance			5,969
Loans - Excluding OBS Credit Exposure [Member] | Cumulative Effect, Period of Adoption, Adjustment | Equipment lease financing, other and overdrafts
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance			$ 3,784