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, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance		$ 146,948	$ 159,131	$ 142,222	$ 152,419
Allowance for Loan and Lease Losses, Write-offs		(808)	(23,767)	(1,689)	(24,582)
Recoveries			283	1,076	560
Provision for credit losses		4,250	5,000	9,250	12,250
Ending balance	[1]	150,859	140,647	150,859	140,647
Allowance for Loan and Lease Loss, Recovery of Bad Debts		469
Provision for Loan and Lease Losses		4,250
Accounts Receivable, Noncurrent, Accrued Interest, Writeoff		112	345	497	425
Commercial And Industrial [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance		20,489	36,932	19,243	27,559
Allowance for Loan and Lease Losses, Write-offs		0	(23,190)	0	(23,471)
Recoveries			16	87	21
Provision for credit losses			1,384	1,554	11,033
Ending balance	[1]	20,884	15,142	20,884	15,142
Allowance for Loan and Lease Loss, Recovery of Bad Debts		2
Provision for Loan and Lease Losses		393
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance		77,929	76,198	74,148	77,799
Allowance for Loan and Lease Losses, Write-offs		0	0	0	0
Recoveries			0	0	0
Provision for credit losses			2,198	6,353	597
Ending balance	[1]	80,501	78,396	80,501	78,396
Allowance for Loan and Lease Loss, Recovery of Bad Debts		0
Provision for Loan and Lease Losses		2,572
Construction Loans [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance		7,573	9,248	7,683	10,762
Allowance for Loan and Lease Losses, Write-offs		0	0	0	0
Recoveries			0	0	0
Provision for credit losses			(210)	121	(1,724)
Ending balance	[1]	7,804	9,038	7,804	9,038
Allowance for Loan and Lease Loss, Recovery of Bad Debts		0
Provision for Loan and Lease Losses		231
Small Business [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance		4,028	3,338	3,963	2,834
Allowance for Loan and Lease Losses, Write-offs		(60)	(59)	(169)	(87)
Recoveries			8	51	39
Provision for credit losses			319	214	820
Ending balance	[1]	4,059	3,606	4,059	3,606
Allowance for Loan and Lease Loss, Recovery of Bad Debts		12
Provision for Loan and Lease Losses		79
Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance		24,180	20,454	23,637	20,973
Allowance for Loan and Lease Losses, Write-offs		0	0	0	0
Recoveries			0	0	0
Provision for credit losses			1,011	1,199	492
Ending balance	[1]	24,836	21,465	24,836	21,465
Allowance for Loan and Lease Loss, Recovery of Bad Debts		0
Provision for Loan and Lease Losses		656
Home Equity Loan [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance		12,042	12,428	12,797	11,504
Allowance for Loan and Lease Losses, Write-offs		(11)	0	(11)	0
Recoveries			10	281	26
Provision for credit losses			(5)	(1,312)	903
Ending balance	[1]	11,755	12,433	11,755	12,433
Allowance for Loan and Lease Loss, Recovery of Bad Debts		148
Provision for Loan and Lease Losses		(424)
Consumer - Other [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance		707	533	751	988
Allowance for Loan and Lease Losses, Write-offs		(737)	(518)	(1,509)	(1,024)
Recoveries			249	657	474
Provision for credit losses			303	1,121	129
Ending balance	[1]	1,020	$ 567	$ 1,020	$ 567
Allowance for Loan and Lease Loss, Recovery of Bad Debts		307
Provision for Loan and Lease Losses		$ 743

[1] Balances of accrued interest receivable excluded from amortized cost and the calculation of allowance for credit losses amounted to $59.2 million and $54.0 million as of June 30, 2024 and June 30, 2023, respectively.