LOANS AND CREDIT QUALITY (Aging of Recorded Investment) (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Loans	$ 5,289,096	$ 5,332,852
Nonaccrual Loans	14,386	11,018
Total Past Due and Nonaccrual	31,553	35,303
Nonaccrual Loans with No ACL	13,180	9,996
Accruing Loans 30 - 59 Days Past Due
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Loans	11,246	18,056
Accruing Loans 60 - 89 Days Past Due
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Loans	4,369	5,455
Accruing Loans 90+  Days Past Due
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Loans	1,552	774
Financial Asset, Not Past Due
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Loans	5,257,543	5,297,549
Commercial and industrial: | Other
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Loans	594,592	606,936
Nonaccrual Loans	591	414
Total Past Due and Nonaccrual	1,270	3,602
Nonaccrual Loans with No ACL	0	0
Commercial and industrial: | Other | Accruing Loans 30 - 59 Days Past Due
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Loans	461	2,978
Commercial and industrial: | Other | Accruing Loans 60 - 89 Days Past Due
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Loans	218	210
Commercial and industrial: | Other | Accruing Loans 90+  Days Past Due
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Loans	0	0
Commercial and industrial: | Other | Financial Asset, Not Past Due
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Loans	593,322	603,334
Real Estate | Construction
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Loans	213,191	145,211
Nonaccrual Loans	0	0
Total Past Due and Nonaccrual	0	0
Nonaccrual Loans with No ACL	0	0
Real Estate | Construction | Accruing Loans 30 - 59 Days Past Due
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Loans	0	0
Real Estate | Construction | Accruing Loans 60 - 89 Days Past Due
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Loans	0	0
Real Estate | Construction | Accruing Loans 90+  Days Past Due
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Loans	0	0
Real Estate | Construction | Financial Asset, Not Past Due
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Loans	213,191	145,211
Real Estate | Residential mortgage
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Loans	1,839,191	1,892,520
Nonaccrual Loans	10,572	9,044
Total Past Due and Nonaccrual	19,665	21,563
Nonaccrual Loans with No ACL	10,572	9,044
Real Estate | Residential mortgage | Accruing Loans 30 - 59 Days Past Due
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Loans	6,399	8,880
Real Estate | Residential mortgage | Accruing Loans 60 - 89 Days Past Due
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Loans	2,030	3,316
Real Estate | Residential mortgage | Accruing Loans 90+  Days Past Due
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Loans	664	323
Real Estate | Residential mortgage | Financial Asset, Not Past Due
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Loans	1,819,526	1,870,957
Real Estate | Home equity
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Loans	600,082	676,982
Nonaccrual Loans	2,608	952
Total Past Due and Nonaccrual	4,931	2,458
Nonaccrual Loans with No ACL	2,608	952
Real Estate | Home equity | Accruing Loans 30 - 59 Days Past Due
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Loans	1,029	943
Real Estate | Home equity | Accruing Loans 60 - 89 Days Past Due
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Loans	809	485
Real Estate | Home equity | Accruing Loans 90+  Days Past Due
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Loans	485	78
Real Estate | Home equity | Financial Asset, Not Past Due
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Loans	595,151	674,524
Real Estate | Commercial mortgage
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Loans	1,594,433	1,500,680
Nonaccrual Loans	0	0
Total Past Due and Nonaccrual	0	0
Nonaccrual Loans with No ACL	0	0
Real Estate | Commercial mortgage | Accruing Loans 30 - 59 Days Past Due
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Loans	0	0
Real Estate | Commercial mortgage | Accruing Loans 60 - 89 Days Past Due
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Loans	0	0
Real Estate | Commercial mortgage | Accruing Loans 90+  Days Past Due
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Loans	0	0
Real Estate | Commercial mortgage | Financial Asset, Not Past Due
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Loans	1,594,433	1,500,680
Consumer | Consumer
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Loans	447,607	510,523
Nonaccrual Loans	615	608
Total Past Due and Nonaccrual	5,687	7,680
Nonaccrual Loans with No ACL	0	0
Consumer | Consumer | Accruing Loans 30 - 59 Days Past Due
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Loans	3,357	5,255
Consumer | Consumer | Accruing Loans 60 - 89 Days Past Due
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Loans	1,312	1,444
Consumer | Consumer | Accruing Loans 90+  Days Past Due
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Loans	403	373
Consumer | Consumer | Financial Asset, Not Past Due
Aging Analysis of Accruing and Non-Accruing Loans and Leases
Loans	$ 441,920	$ 502,843