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Note 4 - Loans Receivable - Risk Categories of Loans By Class of Loans (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | 12 Months Ended
--- | --- | --- | ---
Sep. 30, 2025 | Sep. 30, 2024 | Sep. 30, 2025 | Sep. 30, 2024 | Dec. 31, 2024
Loans receivable | $ 768,646 |  | $ 768,646 |  | $ 895,157
Current period recoveries, total | 10 | $ 28 | 35 | $ 55 |
Current period gross charge-offs, total | (102) | $ (743) | (582) | $ (936) |
Real Estate Portfolio [Member] | One-to-Four Family Residential Real Estate [Member] |  |  |  |  |
Loans receivable | 12,859 |  | 12,859 |  | 14,829
Financing Receivable, current year | 351 |  | 351 |  | 0
Financing Receivable, one year before | 0 |  | 0 |  | 484
Financing Receivable, two years before | 480 |  | 480 |  | 0
Financing Receivable, three years before | 0 |  | 0 |  | 0
Financing Receivable, four years before | 0 |  | 0 |  | 34
Financing Receivable, prior | 9,136 |  | 9,136 |  | 11,089
Financing Receivable, revolving | 2,892 |  | 2,892 |  | 3,222
Current period recoveries, current year |  |  | 0 |  | 0
Current period recoveries, one year before |  |  | 0 |  | 0
Current period recoveries, two years before |  |  | 0 |  | 0
Current period recoveries, three years before |  |  | 0 |  | 0
Current period recoveries, four years before |  |  | 0 |  | 0
Current period recoveries, prior |  |  | 8 |  | 28
Current period recoveries, revolving |  |  | 0 |  | 0
Current period recoveries, total |  |  | 8 |  | 28
Real Estate Portfolio [Member] | Multi-family Mortgage [Member] |  |  |  |  |
Loans receivable | 486,050 |  | 486,050 |  | 521,957
Financing Receivable, current year | 8,420 |  | 8,420 |  | 33,812
Financing Receivable, one year before | 32,511 |  | 32,511 |  | 38,444
Financing Receivable, two years before | 33,624 |  | 33,624 |  | 204,590
Financing Receivable, three years before | 188,345 |  | 188,345 |  | 107,420
Financing Receivable, four years before | 100,652 |  | 100,652 |  | 55,129
Financing Receivable, prior | 118,014 |  | 118,014 |  | 76,940
Financing Receivable, revolving | 4,484 |  | 4,484 |  | 5,622
Current period recoveries, current year |  |  | 0 |  | 0
Current period recoveries, one year before |  |  | 0 |  | 0
Current period recoveries, two years before |  |  | 0 |  | 0
Current period recoveries, three years before |  |  | 0 |  | 0
Current period recoveries, four years before |  |  | 0 |  | 0
Current period recoveries, prior |  |  | 8 |  | 18
Current period recoveries, revolving |  |  | 0 |  | 0
Current period recoveries, total |  |  | 8 |  | 18
Current period gross charge-offs |  |  | 0 |  | 0
Current period gross charge-offs, one year before |  |  | 0 |  | 0
Current period gross charge-offs, two years before |  |  | 0 |  | (5)
Current period gross charge-offs, three years before |  |  | (297) |  | 0
Current period gross charge-offs, four years before |  |  | 0 |  | 0
Current period gross charge-offs, prior |  |  | 0 |  | 0
Current period gross charge-offs, revolving |  |  | 0 |  | 0
Current period gross charge-offs, total |  |  | (297) |  | (5)
Net period recoveries (charge offs), current year |  |  | 0 |  | 0
Net period recoveries (charge offs), one year before |  |  | 0 |  | 0
Net period recoveries (charge offs), two years before |  |  | 0 |  | (5)
Net period recoveries (charge offs), three years before |  |  | (297) |  | 0
Net period recoveries (charge offs), four years before |  |  | 0 |  | 0
Net period recoveries (charge offs), prior |  |  | 8 |  | 18
Net period recoveries (charge offs), revolving |  |  | 0 |  | 0
Current period gross charge-offs (recovery), net |  |  | (289) |  |
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Recovery (Writeoff), Net |  |  |  |  | 13
Real Estate Portfolio [Member] | Nonresidential Real Estate [Member] |  |  |  |  |
Loans receivable | 98,804 |  | 98,804 |  | 108,153
Financing Receivable, current year | 1,074 |  | 1,074 |  | 16,760
Financing Receivable, one year before | 12,322 |  | 12,322 |  | 14,355
Financing Receivable, two years before | 14,015 |  | 14,015 |  | 47,580
Financing Receivable, three years before | 46,089 |  | 46,089 |  | 14,771
Financing Receivable, four years before | 13,994 |  | 13,994 |  | 7,335
Financing Receivable, prior | 10,302 |  | 10,302 |  | 6,439
Financing Receivable, revolving | 1,008 |  | 1,008 |  | 913
Commercial Portfolio Segment [Member] |  |  |  |  |
Loans receivable | 169,335 |  | 169,335 |  | 248,595
Financing Receivable, current year | 15,146 |  | 15,146 |  | 27,360
Financing Receivable, one year before | 20,382 |  | 20,382 |  | 32,572
Financing Receivable, two years before | 20,412 |  | 20,412 |  | 87,396
Financing Receivable, three years before | 52,178 |  | 52,178 |  | 30,804
Financing Receivable, four years before | 16,311 |  | 16,311 |  | 10,131
Financing Receivable, prior | 1,398 |  | 1,398 |  | 723
Financing Receivable, revolving | 43,508 |  | 43,508 |  | 59,609
Current period recoveries, current year |  |  | 0 |  | 0
Current period recoveries, one year before |  |  | 0 |  | 0
Current period recoveries, two years before |  |  | 8 |  | 1
Current period recoveries, three years before |  |  | 7 |  | 5
Current period recoveries, four years before |  |  | 0 |  | 7
Current period recoveries, prior |  |  | 2 |  | 1
Current period recoveries, revolving |  |  | 0 |  | 0
Current period recoveries, total |  |  | 17 |  | 14
Current period gross charge-offs |  |  | (11) |  | 0
Current period gross charge-offs, one year before |  |  | (88) |  | (332)
Current period gross charge-offs, two years before |  |  | (11) |  | (4,998)
Current period gross charge-offs, three years before |  |  | (142) |  | (44)
Current period gross charge-offs, four years before |  |  | (6) |  | (493)
Current period gross charge-offs, prior |  |  | 0 |  | 0
Current period gross charge-offs, revolving |  |  | (1) |  | 0
Current period gross charge-offs, total |  |  | (259) |  | (5,867)
Net period recoveries (charge offs), current year |  |  | (11) |  | 0
Net period recoveries (charge offs), one year before |  |  | (88) |  | (332)
Net period recoveries (charge offs), two years before |  |  | (3) |  | (4,997)
Net period recoveries (charge offs), three years before |  |  | (135) |  | (39)
Net period recoveries (charge offs), four years before |  |  | (6) |  | (486)
Net period recoveries (charge offs), prior |  |  | 2 |  | 1
Net period recoveries (charge offs), revolving |  |  | (1) |  | 0
Current period gross charge-offs (recovery), net |  |  | (242) |  |
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Recovery (Writeoff), Net |  |  |  |  | (5,853)
Consumer Portfolio Segment [Member] |  |  |  |  |
Loans receivable | 1,598 |  | 1,598 |  | 1,623
Financing Receivable, current year | 195 |  | 195 |  | 790
Financing Receivable, one year before | 573 |  | 573 |  | 169
Financing Receivable, two years before | 142 |  | 142 |  | 3
Financing Receivable, three years before | 3 |  | 3 |  | 20
Financing Receivable, four years before | 0 |  | 0 |  | 49
Financing Receivable, prior | 0 |  | 0 |  | 0
Financing Receivable, revolving | 685 |  | 685 |  | 592
Current period recoveries, current year |  |  | 0 |  | 0
Current period recoveries, one year before |  |  | 0 |  | 0
Current period recoveries, two years before |  |  | 0 |  | 0
Current period recoveries, three years before |  |  | 0 |  | 0
Current period recoveries, four years before |  |  | 0 |  | 0
Current period recoveries, prior |  |  | 0 |  | 0
Current period recoveries, revolving |  |  | 2 |  | 1
Current period recoveries, total |  |  | 2 |  | 1
Current period gross charge-offs |  |  | 0 |  | 0
Current period gross charge-offs, one year before |  |  | 0 |  | 0
Current period gross charge-offs, two years before |  |  | 0 |  | 0
Current period gross charge-offs, three years before |  |  | 0 |  | 0
Current period gross charge-offs, four years before |  |  | 0 |  | 0
Current period gross charge-offs, prior |  |  | 0 |  | 0
Current period gross charge-offs, revolving |  |  | (26) |  | (44)
Current period gross charge-offs, total |  |  | (26) |  | (44)
Net period recoveries (charge offs), current year |  |  | 0 |  | 0
Net period recoveries (charge offs), one year before |  |  | 0 |  | 0
Net period recoveries (charge offs), two years before |  |  | 0 |  | 0
Net period recoveries (charge offs), three years before |  |  | 0 |  | 0
Net period recoveries (charge offs), four years before |  |  | 0 |  | 0
Net period recoveries (charge offs), prior |  |  | 0 |  | 0
Net period recoveries (charge offs), revolving |  |  | (24) |  | (43)
Current period gross charge-offs (recovery), net |  |  | (24) |  |
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Recovery (Writeoff), Net |  |  |  |  | (43)
Pass [Member] |  |  |  |  |
Loans receivable | 747,406 |  | 747,406 |  | 866,318
Pass [Member] | Real Estate Portfolio [Member] | One-to-Four Family Residential Real Estate [Member] |  |  |  |  |
Loans receivable | 12,425 |  | 12,425 |  | 14,485
Financing Receivable, current year | 70 |  | 70 |  | 0
Financing Receivable, one year before | 0 |  | 0 |  | 484
Financing Receivable, two years before | 480 |  | 480 |  | 0
Financing Receivable, three years before | 0 |  | 0 |  | 0
Financing Receivable, four years before | 0 |  | 0 |  | 34
Financing Receivable, prior | 9,067 |  | 9,067 |  | 10,897
Financing Receivable, revolving | 2,808 |  | 2,808 |  | 3,070
Pass [Member] | Real Estate Portfolio [Member] | Multi-family Mortgage [Member] |  |  |  |  |
Loans receivable | 477,584 |  | 477,584 |  | 515,478
Financing Receivable, current year | 8,420 |  | 8,420 |  | 33,812
Financing Receivable, one year before | 32,511 |  | 32,511 |  | 38,228
Financing Receivable, two years before | 33,624 |  | 33,624 |  | 199,495
Financing Receivable, three years before | 184,506 |  | 184,506 |  | 107,420
Financing Receivable, four years before | 96,700 |  | 96,700 |  | 55,129
Financing Receivable, prior | 117,339 |  | 117,339 |  | 75,772
Financing Receivable, revolving | 4,484 |  | 4,484 |  | 5,622
Pass [Member] | Real Estate Portfolio [Member] | Nonresidential Real Estate [Member] |  |  |  |  |
Loans receivable | 97,614 |  | 97,614 |  | 106,891
Financing Receivable, current year | 1,074 |  | 1,074 |  | 16,760
Financing Receivable, one year before | 12,322 |  | 12,322 |  | 14,355
Financing Receivable, two years before | 14,015 |  | 14,015 |  | 46,759
Financing Receivable, three years before | 46,089 |  | 46,089 |  | 14,771
Financing Receivable, four years before | 13,994 |  | 13,994 |  | 7,335
Financing Receivable, prior | 9,112 |  | 9,112 |  | 5,998
Financing Receivable, revolving | 1,008 |  | 1,008 |  | 913
Pass [Member] | Commercial Portfolio Segment [Member] |  |  |  |  |
Loans receivable | 158,193 |  | 158,193 |  | 227,851
Financing Receivable, current year | 15,146 |  | 15,146 |  | 27,360
Financing Receivable, one year before | 20,382 |  | 20,382 |  | 32,517
Financing Receivable, two years before | 20,374 |  | 20,374 |  | 72,546
Financing Receivable, three years before | 42,946 |  | 42,946 |  | 30,764
Financing Receivable, four years before | 16,275 |  | 16,275 |  | 9,973
Financing Receivable, prior | 1,397 |  | 1,397 |  | 723
Financing Receivable, revolving | 41,673 |  | 41,673 |  | 53,968
Pass [Member] | Consumer Portfolio Segment [Member] |  |  |  |  |
Loans receivable | 1,590 |  | 1,590 |  | 1,613
Financing Receivable, current year | 195 |  | 195 |  | 788
Financing Receivable, one year before | 572 |  | 572 |  | 169
Financing Receivable, two years before | 142 |  | 142 |  | 3
Financing Receivable, three years before | 3 |  | 3 |  | 20
Financing Receivable, four years before | 0 |  | 0 |  | 49
Financing Receivable, prior | 0 |  | 0 |  | 0
Financing Receivable, revolving | 678 |  | 678 |  | 584
Special Mention [Member] |  |  |  |  |
Loans receivable | 5,583 |  | 5,583 |  | 7,446
Special Mention [Member] | Real Estate Portfolio [Member] | One-to-Four Family Residential Real Estate [Member] |  |  |  |  |
Loans receivable | 281 |  | 281 |  | 0
Financing Receivable, current year | 281 |  | 281 |  |
Financing Receivable, one year before | 0 |  | 0 |  |
Financing Receivable, two years before | 0 |  | 0 |  |
Financing Receivable, three years before | 0 |  | 0 |  |
Financing Receivable, four years before | 0 |  | 0 |  |
Financing Receivable, prior | 0 |  | 0 |  |
Financing Receivable, revolving | 0 |  | 0 |  |
Special Mention [Member] | Real Estate Portfolio [Member] | Multi-family Mortgage [Member] |  |  |  |  |
Loans receivable | 4,514 |  | 4,514 |  | 3,858
Financing Receivable, current year | 0 |  | 0 |  | 0
Financing Receivable, one year before | 0 |  | 0 |  | 0
Financing Receivable, two years before | 0 |  | 0 |  | 3,858
Financing Receivable, three years before | 3,839 |  | 3,839 |  | 0
Financing Receivable, four years before | 0 |  | 0 |  | 0
Financing Receivable, prior | 675 |  | 675 |  | 0
Financing Receivable, revolving | 0 |  | 0 |  | 0
Special Mention [Member] | Real Estate Portfolio [Member] | Nonresidential Real Estate [Member] |  |  |  |  |
Loans receivable | 782 |  | 782 |  | 428
Financing Receivable, current year | 0 |  | 0 |  | 0
Financing Receivable, one year before | 0 |  | 0 |  | 0
Financing Receivable, two years before | 0 |  | 0 |  | 428
Financing Receivable, three years before | 0 |  | 0 |  | 0
Financing Receivable, four years before | 0 |  | 0 |  | 0
Financing Receivable, prior | 782 |  | 782 |  | 0
Financing Receivable, revolving | 0 |  | 0 |  | 0
Special Mention [Member] | Commercial Portfolio Segment [Member] |  |  |  |  |
Loans receivable | 1 |  | 1 |  | 3,156
Financing Receivable, current year | 0 |  | 0 |  | 0
Financing Receivable, one year before | 0 |  | 0 |  | 0
Financing Receivable, two years before | 0 |  | 0 |  | 0
Financing Receivable, three years before | 0 |  | 0 |  | 0
Financing Receivable, four years before | 0 |  | 0 |  | 0
Financing Receivable, prior | 0 |  | 0 |  | 0
Financing Receivable, revolving | 1 |  | 1 |  | 3,156
Special Mention [Member] | Consumer Portfolio Segment [Member] |  |  |  |  |
Loans receivable | 5 |  | 5 |  | 4
Financing Receivable, current year | 0 |  | 0 |  | 0
Financing Receivable, one year before | 0 |  | 0 |  | 0
Financing Receivable, two years before | 0 |  | 0 |  | 0
Financing Receivable, three years before | 0 |  | 0 |  | 0
Financing Receivable, four years before | 0 |  | 0 |  | 0
Financing Receivable, prior | 0 |  | 0 |  | 0
Financing Receivable, revolving | 5 |  | 5 |  | 4
Substandard [Member] |  |  |  |  |
Loans receivable | 6,415 |  | 6,415 |  | 4,459
Substandard [Member] | Real Estate Portfolio [Member] | One-to-Four Family Residential Real Estate [Member] |  |  |  |  |
Loans receivable | 141 |  | 141 |  | 218
Financing Receivable, current year | 0 |  | 0 |  | 0
Financing Receivable, one year before | 0 |  | 0 |  | 0
Financing Receivable, two years before | 0 |  | 0 |  | 0
Financing Receivable, three years before | 0 |  | 0 |  | 0
Financing Receivable, four years before | 0 |  | 0 |  | 0
Financing Receivable, prior | 69 |  | 69 |  | 81
Financing Receivable, revolving | 72 |  | 72 |  | 137
Substandard [Member] | Real Estate Portfolio [Member] | Multi-family Mortgage [Member] |  |  |  |  |
Loans receivable | 3,952 |  | 3,952 |  | 1,168
Financing Receivable, current year | 0 |  | 0 |  | 0
Financing Receivable, one year before | 0 |  | 0 |  | 0
Financing Receivable, two years before | 0 |  | 0 |  | 0
Financing Receivable, three years before | 0 |  | 0 |  | 0
Financing Receivable, four years before | 3,952 |  | 3,952 |  | 0
Financing Receivable, prior | 0 |  | 0 |  | 1,168
Financing Receivable, revolving | 0 |  | 0 |  | 0
Substandard [Member] | Real Estate Portfolio [Member] | Nonresidential Real Estate [Member] |  |  |  |  |
Loans receivable | 408 |  | 408 |  | 441
Financing Receivable, current year | 0 |  | 0 |  | 0
Financing Receivable, one year before | 0 |  | 0 |  | 0
Financing Receivable, two years before | 0 |  | 0 |  | 0
Financing Receivable, three years before | 0 |  | 0 |  | 0
Financing Receivable, four years before | 0 |  | 0 |  | 0
Financing Receivable, prior | 408 |  | 408 |  | 441
Financing Receivable, revolving | 0 |  | 0 |  | 0
Substandard [Member] | Commercial Portfolio Segment [Member] |  |  |  |  |
Loans receivable | 1,911 |  | 1,911 |  | 2,628
Financing Receivable, current year | 0 |  | 0 |  | 0
Financing Receivable, one year before | 0 |  | 0 |  | 0
Financing Receivable, two years before | 0 |  | 0 |  | 103
Financing Receivable, three years before | 76 |  | 76 |  | 40
Financing Receivable, four years before | 0 |  | 0 |  | 0
Financing Receivable, prior | 1 |  | 1 |  | 0
Financing Receivable, revolving | 1,834 |  | 1,834 |  | 2,485
Substandard [Member] | Consumer Portfolio Segment [Member] |  |  |  |  |
Loans receivable | 3 |  | 3 |  | 4
Financing Receivable, current year | 0 |  | 0 |  | 0
Financing Receivable, one year before | 1 |  | 1 |  | 0
Financing Receivable, two years before | 0 |  | 0 |  | 0
Financing Receivable, three years before | 0 |  | 0 |  | 0
Financing Receivable, four years before | 0 |  | 0 |  | 0
Financing Receivable, prior | 0 |  | 0 |  | 0
Financing Receivable, revolving | 2 |  | 2 |  | 4
Substandard Nonaccrual [Member] |  |  |  |  |
Loans receivable | 9,242 |  | 9,242 |  | 16,934
Substandard Nonaccrual [Member] | Real Estate Portfolio [Member] | One-to-Four Family Residential Real Estate [Member] |  |  |  |  |
Loans receivable | 12 |  | 12 |  | 126
Financing Receivable, current year | 0 |  | 0 |  | 0
Financing Receivable, one year before | 0 |  | 0 |  | 0
Financing Receivable, two years before | 0 |  | 0 |  | 0
Financing Receivable, three years before | 0 |  | 0 |  | 0
Financing Receivable, four years before | 0 |  | 0 |  | 0
Financing Receivable, prior | 0 |  | 0 |  | 111
Financing Receivable, revolving | 12 |  | 12 |  | 15
Substandard Nonaccrual [Member] | Real Estate Portfolio [Member] | Multi-family Mortgage [Member] |  |  |  |  |
Loans receivable | 0 |  | 0 |  | 1,453
Financing Receivable, current year |  |  |  |  | 0
Financing Receivable, one year before |  |  |  |  | 216
Financing Receivable, two years before |  |  |  |  | 1,237
Financing Receivable, three years before |  |  |  |  | 0
Financing Receivable, four years before |  |  |  |  | 0
Financing Receivable, prior |  |  |  |  | 0
Financing Receivable, revolving |  |  |  |  | 0
Substandard Nonaccrual [Member] | Real Estate Portfolio [Member] | Nonresidential Real Estate [Member] |  |  |  |  |
Loans receivable | 0 |  | 0 |  | 393
Financing Receivable, current year |  |  |  |  | 0
Financing Receivable, one year before |  |  |  |  | 0
Financing Receivable, two years before |  |  |  |  | 393
Financing Receivable, three years before |  |  |  |  | 0
Financing Receivable, four years before |  |  |  |  | 0
Financing Receivable, prior |  |  |  |  | 0
Financing Receivable, revolving |  |  |  |  | 0
Substandard Nonaccrual [Member] | Commercial Portfolio Segment [Member] |  |  |  |  |
Loans receivable | 9,230 |  | 9,230 |  | 14,960
Financing Receivable, current year | 0 |  | 0 |  | 0
Financing Receivable, one year before | 0 |  | 0 |  | 55
Financing Receivable, two years before | 38 |  | 38 |  | 14,747
Financing Receivable, three years before | 9,156 |  | 9,156 |  | 0
Financing Receivable, four years before | 36 |  | 36 |  | 158
Financing Receivable, prior | 0 |  | 0 |  | 0
Financing Receivable, revolving | 0 |  | 0 |  | 0
Substandard Nonaccrual [Member] | Consumer Portfolio Segment [Member] |  |  |  |  |
Loans receivable | $ 0 |  | $ 0 |  | 2
Financing Receivable, current year |  |  |  |  | 2
Financing Receivable, one year before |  |  |  |  | 0
Financing Receivable, two years before |  |  |  |  | 0
Financing Receivable, three years before |  |  |  |  | 0
Financing Receivable, four years before |  |  |  |  | 0
Financing Receivable, prior |  |  |  |  | 0
Financing Receivable, revolving |  |  |  |  | $ 0

X
- Definition Amount, excluding accrued interest, of decrease in allowance for credit loss on financing receivable from recovery (writeoff). Excludes net investment in lease. + References No definition available. + Details
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Balance Type: | credit
Period Type: | duration

X
- Definition Amount, excluding accrued interest, of recovery of financing receivable originated more than five years before current fiscal year. Excludes net investment in lease. + References No definition available. + Details
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Namespace Prefix: | bfin_
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X
- Definition Amount, excluding accrued interest, of recovery (writeoff) of financing receivable originated more than five years before current fiscal year. Excludes net investment in lease. + References No definition available. + Details
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- Definition Amount, excluding accrued interest, of recovery of financing receivable that can be withdrawn, repaid, and redrawn. + References No definition available. + Details
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Namespace Prefix: | bfin_
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X
- Definition Amount, excluding accrued interest, of recovery (writeoff) of financing receivable that can be withdrawn, repaid, and redrawn. + References No definition available. + Details
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X
- Definition Amount, excluding accrued interest, of recovery of financing receivable originated four years before current fiscal year. Excludes net investment in lease. + References No definition available. + Details
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Namespace Prefix: | bfin_
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- Definition Amount, excluding accrued interest, of recovery (writeoff) of financing receivable originated four years before current fiscal year. Excludes net investment in lease. + References No definition available. + Details
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Namespace Prefix: | bfin_
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