Loans, Allowance for Credit Losses and Credit Quality Financing Receivable, Allowance for Credit Loss (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	$ 112,176	$ 112,176	$ 92,376	$ 67,740
Financing Receivable, Allowance for Credit Losses, Effect of Change in Method		(1,137)
Financing Receivable, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase		1,157
Allowance for Loan and Lease Losses, Write-offs	(710)	(1,444)
Allowance for Loan and Lease Loss, Recovery of Bad Debts	510	860
Provision for Loan and Lease Losses	20,000	45,000
Commercial And Industrial [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	25,662	25,662	21,649	17,594
Financing Receivable, Allowance for Credit Losses, Effect of Change in Method		(1,984)
Financing Receivable, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase		49
Allowance for Loan and Lease Losses, Write-offs	0	0
Allowance for Loan and Lease Loss, Recovery of Bad Debts	4	46
Provision for Loan and Lease Losses	4,009	9,957
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	36,956	36,956	29,498	32,935
Financing Receivable, Allowance for Credit Losses, Effect of Change in Method		(13,048)
Financing Receivable, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase		337
Allowance for Loan and Lease Losses, Write-offs	0	0
Allowance for Loan and Lease Loss, Recovery of Bad Debts	0	0
Provision for Loan and Lease Losses	7,458	16,732
Construction Loans [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	4,501	4,501	3,747	6,053
Financing Receivable, Allowance for Credit Losses, Effect of Change in Method		(3,652)
Financing Receivable, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase		0
Allowance for Loan and Lease Losses, Write-offs	0	0
Allowance for Loan and Lease Loss, Recovery of Bad Debts	0	0
Provision for Loan and Lease Losses	754	2,100
Small Business [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	4,561	4,561	3,829	1,746
Financing Receivable, Allowance for Credit Losses, Effect of Change in Method		495
Financing Receivable, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase		0
Allowance for Loan and Lease Losses, Write-offs	(36)	(145)
Allowance for Loan and Lease Loss, Recovery of Bad Debts	3	6
Provision for Loan and Lease Losses	765	2,459
Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	15,046	15,046	14,847	3,440
Financing Receivable, Allowance for Credit Losses, Effect of Change in Method		9,828
Financing Receivable, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase		423
Allowance for Loan and Lease Losses, Write-offs	0	0
Allowance for Loan and Lease Loss, Recovery of Bad Debts	0	1
Provision for Loan and Lease Losses	199	1,354
Home Equity Line of Credit [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	24,860	24,860	17,910	5,576
Financing Receivable, Allowance for Credit Losses, Effect of Change in Method		7,012
Financing Receivable, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase		319
Allowance for Loan and Lease Losses, Write-offs	(4)	(142)
Allowance for Loan and Lease Loss, Recovery of Bad Debts	95	153
Provision for Loan and Lease Losses	6,859	11,942
Consumer - Other [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	590	590	$ 896	$ 396
Financing Receivable, Allowance for Credit Losses, Effect of Change in Method		212
Financing Receivable, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase		29
Allowance for Loan and Lease Losses, Write-offs	(670)	(1,157)
Allowance for Loan and Lease Loss, Recovery of Bad Debts	408	654
Provision for Loan and Lease Losses	$ (44)	$ 456