v3.26.3
ALLOWANCE FOR CREDIT LOSSES - Changes in the Allowance for Credit Losses (Details) - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Financing Receivable, Allowance for Credit Loss [Line Items]        
Balance at beginning of year $ 189,912 $ 158,522 $ 186,487 $ 156,791
Provision for Credit Losses-loans and leases 8,975 8,612 27,938 26,837
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff 8,543 7,676 29,522 26,516
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Recovery 1,306 2,458 3,918 4,804
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff (Recovery) 7,237 5,218 25,604 21,712
Balance at end of year 191,650 161,916 191,650 161,916
BankFinancial        
Financing Receivable, Allowance for Credit Loss [Line Items]        
Balance at beginning of year     2,829  
Commercial        
Financing Receivable, Allowance for Credit Loss [Line Items]        
Balance at beginning of year 69,482 53,395 75,155 49,987
Provision for Credit Losses-loans and leases 8,027 8,968 13,282 25,065
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff 984 2,165 14,209 15,339
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Recovery 387 202 950 687
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff (Recovery) 597 1,963 13,259 14,652
Balance at end of year 76,912 60,400 76,912 60,400
Commercial | BankFinancial        
Financing Receivable, Allowance for Credit Loss [Line Items]        
Balance at beginning of year     1,734  
Lease financing        
Financing Receivable, Allowance for Credit Loss [Line Items]        
Balance at beginning of year 14,971 13,907 15,162 13,079
Provision for Credit Losses-loans and leases 684 475 1,713 3,323
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff 976 298 2,333 2,358
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Recovery 0 291 137 331
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff (Recovery) 976 7 2,196 2,027
Balance at end of year 14,679 14,375 14,679 14,375
Lease financing | BankFinancial        
Financing Receivable, Allowance for Credit Loss [Line Items]        
Balance at beginning of year     0  
Construction real estate        
Financing Receivable, Allowance for Credit Loss [Line Items]        
Balance at beginning of year 15,372 18,908 16,951 19,216
Provision for Credit Losses-loans and leases (2,546) (3,034) (4,125) (3,342)
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff 110 245 110 245
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Recovery 0 0 0 0
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff (Recovery) 110 245 110 245
Balance at end of year 12,716 15,629 12,716 15,629
Construction real estate | BankFinancial        
Financing Receivable, Allowance for Credit Loss [Line Items]        
Balance at beginning of year     0  
Commercial real estate        
Financing Receivable, Allowance for Credit Loss [Line Items]        
Balance at beginning of year 50,565 34,133 38,389 35,721
Provision for Credit Losses-loans and leases 3,337 2,147 17,083 465
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff 5,129 3,105 7,642 3,105
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Recovery 8 1,138 44 1,232
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff (Recovery) 5,121 1,967 7,598 1,873
Balance at end of year 48,781 34,313 48,781 34,313
Commercial real estate | BankFinancial        
Financing Receivable, Allowance for Credit Loss [Line Items]        
Balance at beginning of year     907  
Residential Portfolio Segment [Member]        
Financing Receivable, Allowance for Credit Loss [Line Items]        
Balance at beginning of year 15,600 17,089 18,084 17,822
Provision for Credit Losses-loans and leases (533) (1,567) (2,908) (2,350)
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff 11 0 222 16
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Recovery 24 58 72 124
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff (Recovery) (13) (58) 150 (108)
Balance at end of year 15,080 15,580 15,080 15,580
Residential Portfolio Segment [Member] | BankFinancial        
Financing Receivable, Allowance for Credit Loss [Line Items]        
Balance at beginning of year     54  
Home equity        
Financing Receivable, Allowance for Credit Loss [Line Items]        
Balance at beginning of year 17,400 15,820 16,035 14,774
Provision for Credit Losses-loans and leases (583) 454 848 1,468
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff 137 92 518 278
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Recovery 60 94 333 312
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff (Recovery) 77 (2) 185 (34)
Balance at end of year 16,740 16,276 16,740 16,276
Home equity | BankFinancial        
Financing Receivable, Allowance for Credit Loss [Line Items]        
Balance at beginning of year     42  
Installment        
Financing Receivable, Allowance for Credit Loss [Line Items]        
Balance at beginning of year 3,450 2,808 3,874 3,564
Provision for Credit Losses-loans and leases (49) 385 360 791
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff 676 1,194 2,768 3,635
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Recovery 688 609 1,946 1,888
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff (Recovery) (12) 585 822 1,747
Balance at end of year 3,413 2,608 3,413 2,608
Installment | BankFinancial        
Financing Receivable, Allowance for Credit Loss [Line Items]        
Balance at beginning of year     1  
Credit card        
Financing Receivable, Allowance for Credit Loss [Line Items]        
Balance at beginning of year 3,072 2,462 2,837 2,628
Provision for Credit Losses-loans and leases 638 784 1,685 1,417
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff 520 577 1,720 1,540
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Recovery 139 66 436 230
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff (Recovery) (381) (511) (1,284) (1,310)
Balance at end of year $ 3,329 $ 2,735 3,329 $ 2,735
Credit card | BankFinancial        
Financing Receivable, Allowance for Credit Loss [Line Items]        
Balance at beginning of year     $ 91