v3.26.3
ALLOWANCE FOR CREDIT LOSSES AND CREDIT QUALITY INFORMATION - Schedule of Allowance for Loan Losses and Loan Balances (Details) - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended 12 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Dec. 31, 2025
Allowance for credit losses          
Beginning balance $ 177,263 $ 186,304 $ 179,647 $ 195,281 $ 195,281
Charge-offs 8,532 12,353 32,183 48,020  
Recoveries 9,100 3,267 29,096 13,272  
Charge-offs arising from transfer of loans to held for sale   (826)   (9,481)  
Provision 7,407 6,838 8,678 32,178  
Ending balance 185,238 183,230 185,238 183,230 179,647
Period-end allowance allocated to:          
Loans evaluated on an individual basis 10,117 6,069 10,117 6,069  
Loans evaluated on a collective basis 175,121 177,161 175,121 177,161  
Period-end loan balances:          
Loans evaluated on an individual basis 72,659 65,357 72,659 65,357  
Loans evaluated on a collective basis 13,566,053 12,889,896 13,566,053 12,889,896  
Ending balance 13,638,712 12,955,253 13,638,712 12,955,253 13,257,946
Reverse mortgage, fair value 3,500 5,300 3,500 5,300 3,700
Commercial | Commercial and Industrial          
Allowance for credit losses          
Beginning balance 51,883 52,121 52,927 57,131 57,131
Charge-offs 3,928 7,363 13,334 28,514 32,120
Recoveries 4,992 1,541 21,629 3,985  
Charge-offs arising from transfer of loans to held for sale   0   (552)  
Provision 7,736 3,330 (539) 17,579  
Ending balance 60,683 49,629 60,683 49,629 52,927
Period-end allowance allocated to:          
Loans evaluated on an individual basis 8,082 0 8,082 0  
Loans evaluated on a collective basis 52,601 49,629 52,601 49,629  
Period-end loan balances:          
Loans evaluated on an individual basis 29,639 14,986 29,639 14,986  
Loans evaluated on a collective basis 2,945,441 2,610,166 2,945,441 2,610,166  
Ending balance 2,975,080 2,625,152 2,975,080 2,625,152 2,796,654
Commercial | Owner-occupied commercial          
Allowance for credit losses          
Beginning balance 8,717 8,584 7,626 9,139 9,139
Charge-offs 311 4 609 4 215
Recoveries 1 4 13 16  
Charge-offs arising from transfer of loans to held for sale   0   0  
Provision 627 (273) 2,004 (840)  
Ending balance 9,034 8,311 9,034 8,311 7,626
Period-end allowance allocated to:          
Loans evaluated on an individual basis 0 0 0 0  
Loans evaluated on a collective basis 9,034 8,311 9,034 8,311  
Period-end loan balances:          
Loans evaluated on an individual basis 19,896 6,672 19,896 6,672  
Loans evaluated on a collective basis 2,020,403 1,916,095 2,020,403 1,916,095  
Ending balance 2,040,299 1,922,767 2,040,299 1,922,767 1,937,339
Commercial | Commercial mortgages          
Allowance for credit losses          
Beginning balance 49,451 54,775 48,047 48,962 48,962
Charge-offs 0 43 1,740 240 4,583
Recoveries 2,827 0 3,361 527  
Charge-offs arising from transfer of loans to held for sale   0   0  
Provision (3,196) (6,122) (586) (639)  
Ending balance 49,082 48,610 49,082 48,610 48,047
Period-end allowance allocated to:          
Loans evaluated on an individual basis 0 0 0 0  
Loans evaluated on a collective basis 49,082 48,610 49,082 48,610  
Period-end loan balances:          
Loans evaluated on an individual basis 5,287 3,145 5,287 3,145  
Loans evaluated on a collective basis 3,879,440 3,852,826 3,879,440 3,852,826  
Ending balance 3,884,727 3,855,971 3,884,727 3,855,971 3,916,159
Commercial | Construction          
Allowance for credit losses          
Beginning balance 13,541 10,696 13,264 9,185 9,185
Charge-offs 700 0 4,435 0 4,900
Recoveries 0 0 0 0  
Charge-offs arising from transfer of loans to held for sale   0   0  
Provision 401 6,478 4,413 7,989  
Ending balance 13,242 17,174 13,242 17,174 13,264
Period-end allowance allocated to:          
Loans evaluated on an individual basis 2,035 6,069 2,035 6,069  
Loans evaluated on a collective basis 11,207 11,105 11,207 11,105  
Period-end loan balances:          
Loans evaluated on an individual basis 7,243 29,381 7,243 29,381  
Loans evaluated on a collective basis 997,628 974,605 997,628 974,605  
Ending balance 1,004,871 1,003,986 1,004,871 1,003,986 1,023,911
Commercial | Commercial Small Business Leases          
Allowance for credit losses          
Beginning balance 17,424 18,301 16,449 15,965 15,965
Charge-offs 2,588 3,860 7,925 11,203 14,386
Recoveries 748 932 2,318 2,265  
Charge-offs arising from transfer of loans to held for sale   0   0  
Provision 481 1,892 5,223 10,238  
Ending balance 16,065 17,265 16,065 17,265 16,449
Period-end allowance allocated to:          
Loans evaluated on an individual basis 0 0 0 0  
Loans evaluated on a collective basis 16,065 17,265 16,065 17,265  
Period-end loan balances:          
Loans evaluated on an individual basis 0 0 0 0  
Loans evaluated on a collective basis 593,112 617,256 593,112 617,256  
Ending balance 593,112 617,256 593,112 617,256 603,321
Residential          
Allowance for credit losses          
Beginning balance 6,260 5,815 6,764 5,566 5,566
Charge-offs 0 0 0 0 0
Recoveries 41 43 135 140  
Charge-offs arising from transfer of loans to held for sale   0   0  
Provision (318) 594 (916) 746  
Ending balance 5,983 6,452 5,983 6,452 6,764
Period-end allowance allocated to:          
Loans evaluated on an individual basis 0 0 0 0  
Loans evaluated on a collective basis 5,983 6,452 5,983 6,452  
Period-end loan balances:          
Loans evaluated on an individual basis 6,961 8,149 6,961 8,149  
Loans evaluated on a collective basis 1,320,862 1,025,194 1,320,862 1,025,194  
Ending balance 1,327,823 1,033,343 1,327,823 1,033,343 1,086,102
Consumer          
Allowance for credit losses          
Beginning balance 29,987 36,012 34,570 49,333 49,333
Charge-offs 1,005 1,083 4,140 8,059 18,863
Recoveries 491 747 1,640 6,339  
Charge-offs arising from transfer of loans to held for sale   (826)   (8,929)  
Provision 1,676 939 (921) (2,895)  
Ending balance 31,149 35,789 31,149 35,789 34,570
Period-end allowance allocated to:          
Loans evaluated on an individual basis 0 0 0 0  
Loans evaluated on a collective basis 31,149 35,789 31,149 35,789  
Period-end loan balances:          
Loans evaluated on an individual basis 3,633 3,024 3,633 3,024  
Loans evaluated on a collective basis 1,809,167 1,893,754 1,809,167 1,893,754  
Ending balance $ 1,812,800 $ 1,896,778 $ 1,812,800 $ 1,896,778 $ 1,894,460