v3.26.3
LOANS AND CREDIT QUALITY (Aging of Recorded Investment) (Details) - USD ($)
$ in Thousands
Sep. 30, 2026
Dec. 31, 2025
Aging Analysis of Accruing and Non-Accruing Loans and Leases    
Loans Past Due $ 5,313,070 $ 5,289,096
Nonaccrual Loans 13,037 14,386
Total Past Due and Nonaccrual 58,405 31,553
Nonaccrual Loans With No ACL 12,293 13,180
Accruing Loans 30 - 59 Days Past Due    
Aging Analysis of Accruing and Non-Accruing Loans and Leases    
Loans Past Due 39,438 11,246
Accruing Loans 60 - 89 Days Past Due    
Aging Analysis of Accruing and Non-Accruing Loans and Leases    
Loans Past Due 5,409 4,369
Accruing Loans 90 Days or More Past Due    
Aging Analysis of Accruing and Non-Accruing Loans and Leases    
Loans Past Due 521 1,552
Current Loans    
Aging Analysis of Accruing and Non-Accruing Loans and Leases    
Loans Past Due 5,254,665 5,257,543
Commercial and Industrial    
Aging Analysis of Accruing and Non-Accruing Loans and Leases    
Loans Past Due 578,574 594,592
Nonaccrual Loans 138 591
Total Past Due and Nonaccrual 1,559 1,270
Nonaccrual Loans With No ACL 0 0
Commercial and Industrial | Accruing Loans 30 - 59 Days Past Due    
Aging Analysis of Accruing and Non-Accruing Loans and Leases    
Loans Past Due 968 461
Commercial and Industrial | Accruing Loans 60 - 89 Days Past Due    
Aging Analysis of Accruing and Non-Accruing Loans and Leases    
Loans Past Due 453 218
Commercial and Industrial | Accruing Loans 90 Days or More Past Due    
Aging Analysis of Accruing and Non-Accruing Loans and Leases    
Loans Past Due 0 0
Commercial and Industrial | Current Loans    
Aging Analysis of Accruing and Non-Accruing Loans and Leases    
Loans Past Due 577,015 593,322
Real Estate Portfolio Segment | Construction    
Aging Analysis of Accruing and Non-Accruing Loans and Leases    
Loans Past Due 217,144 213,191
Nonaccrual Loans 0 0
Total Past Due and Nonaccrual 0 0
Nonaccrual Loans With No ACL 0 0
Real Estate Portfolio Segment | Construction | Accruing Loans 30 - 59 Days Past Due    
Aging Analysis of Accruing and Non-Accruing Loans and Leases    
Loans Past Due 0 0
Real Estate Portfolio Segment | Construction | Accruing Loans 60 - 89 Days Past Due    
Aging Analysis of Accruing and Non-Accruing Loans and Leases    
Loans Past Due 0 0
Real Estate Portfolio Segment | Construction | Accruing Loans 90 Days or More Past Due    
Aging Analysis of Accruing and Non-Accruing Loans and Leases    
Loans Past Due 0 0
Real Estate Portfolio Segment | Construction | Current Loans    
Aging Analysis of Accruing and Non-Accruing Loans and Leases    
Loans Past Due 217,144 213,191
Real Estate Portfolio Segment | Residential mortgage    
Aging Analysis of Accruing and Non-Accruing Loans and Leases    
Loans Past Due 1,802,348 1,839,191
Nonaccrual Loans 9,620 10,572
Total Past Due and Nonaccrual 12,104 19,665
Nonaccrual Loans With No ACL 9,620 10,572
Real Estate Portfolio Segment | Residential mortgage | Accruing Loans 30 - 59 Days Past Due    
Aging Analysis of Accruing and Non-Accruing Loans and Leases    
Loans Past Due 0 6,399
Real Estate Portfolio Segment | Residential mortgage | Accruing Loans 60 - 89 Days Past Due    
Aging Analysis of Accruing and Non-Accruing Loans and Leases    
Loans Past Due 2,484 2,030
Real Estate Portfolio Segment | Residential mortgage | Accruing Loans 90 Days or More Past Due    
Aging Analysis of Accruing and Non-Accruing Loans and Leases    
Loans Past Due 0 664
Real Estate Portfolio Segment | Residential mortgage | Current Loans    
Aging Analysis of Accruing and Non-Accruing Loans and Leases    
Loans Past Due 1,790,244 1,819,526
Real Estate Portfolio Segment | Home Equity    
Aging Analysis of Accruing and Non-Accruing Loans and Leases    
Loans Past Due 568,114 600,082
Nonaccrual Loans 2,673 2,608
Total Past Due and Nonaccrual 6,476 4,931
Nonaccrual Loans With No ACL 2,673 2,608
Real Estate Portfolio Segment | Home Equity | Accruing Loans 30 - 59 Days Past Due    
Aging Analysis of Accruing and Non-Accruing Loans and Leases    
Loans Past Due 2,080 1,029
Real Estate Portfolio Segment | Home Equity | Accruing Loans 60 - 89 Days Past Due    
Aging Analysis of Accruing and Non-Accruing Loans and Leases    
Loans Past Due 1,723 809
Real Estate Portfolio Segment | Home Equity | Accruing Loans 90 Days or More Past Due    
Aging Analysis of Accruing and Non-Accruing Loans and Leases    
Loans Past Due 0 485
Real Estate Portfolio Segment | Home Equity | Current Loans    
Aging Analysis of Accruing and Non-Accruing Loans and Leases    
Loans Past Due 561,638 595,151
Real Estate Portfolio Segment | Commercial mortgage    
Aging Analysis of Accruing and Non-Accruing Loans and Leases    
Loans Past Due 1,713,014 1,594,433
Nonaccrual Loans 0 0
Total Past Due and Nonaccrual 32,691 0
Nonaccrual Loans With No ACL 0 0
Real Estate Portfolio Segment | Commercial mortgage | Accruing Loans 30 - 59 Days Past Due    
Aging Analysis of Accruing and Non-Accruing Loans and Leases    
Loans Past Due 32,691 0
Real Estate Portfolio Segment | Commercial mortgage | Accruing Loans 60 - 89 Days Past Due    
Aging Analysis of Accruing and Non-Accruing Loans and Leases    
Loans Past Due 0 0
Real Estate Portfolio Segment | Commercial mortgage | Accruing Loans 90 Days or More Past Due    
Aging Analysis of Accruing and Non-Accruing Loans and Leases    
Loans Past Due 0 0
Real Estate Portfolio Segment | Commercial mortgage | Current Loans    
Aging Analysis of Accruing and Non-Accruing Loans and Leases    
Loans Past Due 1,680,323 1,594,433
Consumer    
Aging Analysis of Accruing and Non-Accruing Loans and Leases    
Loans Past Due 433,876 447,607
Nonaccrual Loans 606 615
Total Past Due and Nonaccrual 5,575 5,687
Nonaccrual Loans With No ACL 0 0
Consumer | Accruing Loans 30 - 59 Days Past Due    
Aging Analysis of Accruing and Non-Accruing Loans and Leases    
Loans Past Due 3,699 3,357
Consumer | Accruing Loans 60 - 89 Days Past Due    
Aging Analysis of Accruing and Non-Accruing Loans and Leases    
Loans Past Due 749 1,312
Consumer | Accruing Loans 90 Days or More Past Due    
Aging Analysis of Accruing and Non-Accruing Loans and Leases    
Loans Past Due 521 403
Consumer | Current Loans    
Aging Analysis of Accruing and Non-Accruing Loans and Leases    
Loans Past Due $ 428,301 $ 441,920