ACL for Loans - ACL Activity (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, beginning balance	$ 52,640
Provision for credit losses on loans	2,736	$ 530
Allowance for credit losses, ending balance	55,002
Loans Excluding Unfunded Commitments
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, beginning balance	52,640	47,704
Provision for credit losses on loans	2,318	825
Recoveries	133	33
Less: Charge-offs	89	138
Allowance for credit losses, ending balance	55,002	48,424
Commercial real estate | Loans Excluding Unfunded Commitments
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, beginning balance	36,564	31,847
Provision for credit losses on loans	1,161	2,089
Recoveries	0	0
Less: Charge-offs	0	0
Allowance for credit losses, ending balance	37,725	33,936
Commercial and industrial | Loans Excluding Unfunded Commitments
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, beginning balance	8,896	9,574
Provision for credit losses on loans	438	(543)
Recoveries	127	24
Less: Charge-offs	83	105
Allowance for credit losses, ending balance	9,378	8,950
Commercial construction | Loans Excluding Unfunded Commitments
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, beginning balance	3,961	4,090
Provision for credit losses on loans	492	(572)
Recoveries	0	0
Less: Charge-offs	0	0
Allowance for credit losses, ending balance	4,453	3,518
Residential mortgages | Loans Excluding Unfunded Commitments
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, beginning balance	2,255	1,405
Provision for credit losses on loans	123	(83)
Recoveries	0	0
Less: Charge-offs	0	0
Allowance for credit losses, ending balance	2,378	1,322
Home equity loans and lines | Loans Excluding Unfunded Commitments
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, beginning balance	633	465
Provision for credit losses on loans	76	(15)
Recoveries	3	4
Less: Charge-offs	0	0
Allowance for credit losses, ending balance	712	454
Consumer | Loans Excluding Unfunded Commitments
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, beginning balance	331	323
Provision for credit losses on loans	28	(51)
Recoveries	3	5
Less: Charge-offs	6	33
Allowance for credit losses, ending balance	$ 356	$ 244