Loans and Allowance for Credit Losses Allowance for Loan Losses by Portfolio Segment (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Mar. 31, 2020	Jan. 01, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	$ 257,471	$ 170,372	$ 166,209	$ 169,410
Impact of adopting CECL						$ (43,807)
Loans charged off	8,047		22,050
Recoveries of loans previously charged off	3,926		6,813
Current period net charge-offs	(4,121)		(15,237)
Provision for credit losses	19,570		63,600
Ending balance	272,920	176,941	272,920	176,941
Beginning balance		162,109	163,622	160,537
Loans charged off		(3,711)		(10,080)
Recovery of loans previously charged off		5,255		7,486
Net loans recovered (charged off)		1,544		(2,594)
Allowance for loan and lease losses, provision for loss, net of provision applied to unfunded commitments		6,580		12,290
Ending balance	256,537	170,233	256,537	170,233
Provision for Loan and Lease Losses	19,570	5,025	63,600	10,125
Financing Receivable, Allowance for Credit Losses
Accounts, Notes, Loans and Financing Receivable [Line Items]
Provision for Loan and Lease Losses	1,600		2,200
Real estate - commercial mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance		51,946		52,889
Loans charged off		(230)		(1,375)
Recovery of loans previously charged off		169		305
Net loans recovered (charged off)		(61)		(1,070)
Allowance for loan and lease losses, provision for loss, net of provision applied to unfunded commitments		2,974		3,040
Ending balance		54,859		54,859
Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance		60,501		58,868
Loans charged off		(1,895)		(4,682)
Recovery of loans previously charged off		2,680		3,923
Net loans recovered (charged off)		785		(759)
Allowance for loan and lease losses, provision for loss, net of provision applied to unfunded commitments		5,055		8,232
Ending balance		66,341		66,341
Real-estate - home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance		19,215		18,911
Loans charged off		(206)		(425)
Recovery of loans previously charged off		223		420
Net loans recovered (charged off)		17		(5)
Allowance for loan and lease losses, provision for loss, net of provision applied to unfunded commitments		(251)		75
Ending balance		18,981		18,981
Real estate - residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance		19,146		18,921
Loans charged off		(134)		(789)
Recovery of loans previously charged off		211		343
Net loans recovered (charged off)		77		(446)
Allowance for loan and lease losses, provision for loss, net of provision applied to unfunded commitments		(331)		417
Ending balance		18,892		18,892
Real-estate - construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance		4,941		5,061
Loans charged off		(3)		(98)
Recovery of loans previously charged off		1,245		1,329
Net loans recovered (charged off)		1,242		1,231
Allowance for loan and lease losses, provision for loss, net of provision applied to unfunded commitments		(1,255)		(1,364)
Ending balance		4,928		4,928
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance		3,319		3,217
Loans charged off		(795)		(1,478)
Recovery of loans previously charged off		579		789
Net loans recovered (charged off)		(216)		(689)
Allowance for loan and lease losses, provision for loss, net of provision applied to unfunded commitments		260		835
Ending balance		3,363		3,363
Equipment lease financing, other and overdrafts
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance		3,041		2,670
Loans charged off		(448)		(1,233)
Recovery of loans previously charged off		148		377
Net loans recovered (charged off)		(300)		(856)
Allowance for loan and lease losses, provision for loss, net of provision applied to unfunded commitments		128		1,055
Ending balance		$ 2,869		$ 2,869
Cumulative Effect, Period of Adoption, Adjustment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impact of adopting CECL					$ 0	58,348
Loans - Excluding OBS Credit Exposure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	238,508		163,622
Impact of adopting CECL						45,723
Loans charged off	8,047		22,050
Recoveries of loans previously charged off	3,926		6,813
Current period net charge-offs	(4,121)		(15,237)
Provision for credit losses	22,150		62,429
Ending balance	256,537		256,537
Loans - Excluding OBS Credit Exposure [Member] | Real estate - commercial mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	90,319		45,610
Impact of adopting CECL						29,361
Loans charged off	2,324		3,179
Recoveries of loans previously charged off	95		339
Current period net charge-offs	(2,229)		(2,840)
Provision for credit losses	14,605		30,564
Ending balance	102,695		102,695
Loans - Excluding OBS Credit Exposure [Member] | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	63,606		68,602
Impact of adopting CECL						(18,576)
Loans charged off	3,480		14,379
Recoveries of loans previously charged off	2,978		4,712
Current period net charge-offs	(502)		(9,667)
Provision for credit losses	(1,657)		21,088
Ending balance	61,447		61,447
Loans - Excluding OBS Credit Exposure [Member] | Real-estate - home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	15,253		17,744
Impact of adopting CECL						(65)
Loans charged off	458		745
Recoveries of loans previously charged off	44		261
Current period net charge-offs	(414)		(484)
Provision for credit losses	1,552		(804)
Ending balance	16,391		16,391
Loans - Excluding OBS Credit Exposure [Member] | Real estate - residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	42,427		19,771
Impact of adopting CECL						21,235
Loans charged off	235		422
Recoveries of loans previously charged off	112		197
Current period net charge-offs	(123)		(225)
Provision for credit losses	4,139		5,662
Ending balance	46,443		46,443
Loans - Excluding OBS Credit Exposure [Member] | Real-estate - construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	8,398		4,443
Impact of adopting CECL						4,015
Loans charged off	17		17
Recoveries of loans previously charged off	0		70
Current period net charge-offs	(17)		53
Provision for credit losses	3,933		3,803
Ending balance	12,314		12,314
Loans - Excluding OBS Credit Exposure [Member] | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	9,865		3,762
Impact of adopting CECL						5,969
Loans charged off	845		2,087
Recoveries of loans previously charged off	605		1,034
Current period net charge-offs	(240)		(1,053)
Provision for credit losses	674		1,621
Ending balance	10,299		10,299
Loans - Excluding OBS Credit Exposure [Member] | Equipment lease financing, other and overdrafts
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	8,640		3,690
Impact of adopting CECL						$ 3,784
Loans charged off	688		1,221
Recoveries of loans previously charged off	92		200
Current period net charge-offs	(596)		(1,021)
Provision for credit losses	(1,096)		495
Ending balance	$ 6,948		$ 6,948