XML 49 R40.htm IDEA: XBRL DOCUMENT v3.23.3

Note 4 - Loans Receivable - Risk Categories of Loans By Class of Loans (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Loans receivable	$ 1,114,163	$ 1,234,872
Real Estate Portfolio [Member] | One-to-Four Family Residential Real Estate [Member]
Loans receivable	19,233	23,133
Financing Receivable, current year	0
Financing Receivable, one year before	0
Financing Receivable, two years before	0
Financing Receivable, three years before	154
Financing Receivable, four years before	0
Financing Receivable, prior	14,991
Financing Receivable, revolving	4,088
Current period recoveries, current year	0
Current period recoveries, one year before	0
Current period recoveries, two years before	0
Current period recoveries, three years before	0
Current period recoveries, four years before	0
Current period recoveries, prior	44
Current period recoveries, revolving	0
Current period recoveries, total	44
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year, Recovery (Writeoff), Net	0
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year, Recovery (Writeoff), Net	0
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year, Recovery (Writeoff), Net	0
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year, Recovery (Writeoff), Net	0
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year, Recovery (Writeoff), Net	0
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year, Recovery (Writeoff), Net	44
Financing Receivable, Excluding Accrued Interest, Revolving, Recovery (Writeoff), Net	0
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Recovery (Writeoff), Net	44
Real Estate Portfolio [Member] | Multi-family Mortgage [Member]
Loans receivable	528,251	537,394
Financing Receivable, current year	38,554
Financing Receivable, one year before	213,939
Financing Receivable, two years before	113,728
Financing Receivable, three years before	59,423
Financing Receivable, four years before	22,304
Financing Receivable, prior	72,077
Financing Receivable, revolving	8,226
Current period recoveries, current year	0
Current period recoveries, one year before	0
Current period recoveries, two years before	0
Current period recoveries, three years before	0
Current period recoveries, four years before	0
Current period recoveries, prior	15
Current period recoveries, revolving	0
Current period recoveries, total	15
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year, Recovery (Writeoff), Net	0
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year, Recovery (Writeoff), Net	0
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year, Recovery (Writeoff), Net	0
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year, Recovery (Writeoff), Net	0
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year, Recovery (Writeoff), Net	0
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year, Recovery (Writeoff), Net	15
Financing Receivable, Excluding Accrued Interest, Revolving, Recovery (Writeoff), Net	0
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Recovery (Writeoff), Net	15
Real Estate Portfolio [Member] | Nonresidential Real Estate [Member]
Loans receivable	117,641	119,705
Financing Receivable, current year	11,692
Financing Receivable, one year before	53,620
Financing Receivable, two years before	22,169
Financing Receivable, three years before	7,900
Financing Receivable, four years before	9,773
Financing Receivable, prior	12,383
Financing Receivable, revolving	104
Commercial Portfolio Segment [Member]
Loans receivable	447,687	553,056
Financing Receivable, current year	45,112
Financing Receivable, one year before	182,672
Financing Receivable, two years before	78,750
Financing Receivable, three years before	48,106
Financing Receivable, four years before	4,618
Financing Receivable, prior	2,319
Financing Receivable, revolving	86,110
Current period recoveries, current year	0
Current period recoveries, one year before	0
Current period recoveries, two years before	27
Current period recoveries, three years before	0
Current period recoveries, four years before	0
Current period recoveries, prior	0
Current period recoveries, revolving	0
Current period recoveries, total	27
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year, Recovery (Writeoff), Net	(20)
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year, Recovery (Writeoff), Net	(1,586)
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year, Recovery (Writeoff), Net	27
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year, Recovery (Writeoff), Net	0
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year, Recovery (Writeoff), Net	0
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year, Recovery (Writeoff), Net	0
Financing Receivable, Excluding Accrued Interest, Revolving, Recovery (Writeoff), Net	0
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Recovery (Writeoff), Net	(1,579)
Current period gross charge-offs	(20)
Current period gross charge-offs	(1,586)
Current period gross charge-offs	0
Current period gross charge-offs	0
Current period gross charge-offs	0
Current period gross charge-offs	0
Current period gross charge-offs	0
Current period gross charge-offs	(1,606)
Consumer Portfolio Segment [Member]
Loans receivable	1,351	1,584
Financing Receivable, current year	167
Financing Receivable, one year before	11
Financing Receivable, two years before	146
Financing Receivable, three years before	159
Financing Receivable, four years before	278
Financing Receivable, prior	0
Financing Receivable, revolving	590
Current period recoveries, current year	0
Current period recoveries, one year before	0
Current period recoveries, two years before	0
Current period recoveries, three years before	0
Current period recoveries, four years before	0
Current period recoveries, prior	0
Current period recoveries, revolving	1
Current period recoveries, total	1
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year, Recovery (Writeoff), Net	0
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year, Recovery (Writeoff), Net	0
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year, Recovery (Writeoff), Net	0
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year, Recovery (Writeoff), Net	0
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year, Recovery (Writeoff), Net	0
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year, Recovery (Writeoff), Net	0
Financing Receivable, Excluding Accrued Interest, Revolving, Recovery (Writeoff), Net	(42)
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Recovery (Writeoff), Net	(42)
Current period gross charge-offs	0
Current period gross charge-offs	0
Current period gross charge-offs	0
Current period gross charge-offs	0
Current period gross charge-offs	0
Current period gross charge-offs	0
Current period gross charge-offs	(43)
Current period gross charge-offs	(43)
Pass [Member]
Loans receivable	1,048,572	1,198,984
Pass [Member] | Real Estate Portfolio [Member] | One-to-Four Family Residential Real Estate [Member]
Loans receivable	18,870	22,648
Financing Receivable, current year	0
Financing Receivable, one year before	0
Financing Receivable, two years before	0
Financing Receivable, three years before	154
Financing Receivable, four years before	0
Financing Receivable, prior	14,799
Financing Receivable, revolving	3,917
Pass [Member] | Real Estate Portfolio [Member] | Multi-family Mortgage [Member]
Loans receivable	523,406	534,253
Financing Receivable, current year	38,554
Financing Receivable, one year before	211,954
Financing Receivable, two years before	113,728
Financing Receivable, three years before	59,159
Financing Receivable, four years before	22,304
Financing Receivable, prior	69,481
Financing Receivable, revolving	8,226
Pass [Member] | Real Estate Portfolio [Member] | Nonresidential Real Estate [Member]
Loans receivable	113,354	116,635
Financing Receivable, current year	11,692
Financing Receivable, one year before	51,053
Financing Receivable, two years before	20,622
Financing Receivable, three years before	7,900
Financing Receivable, four years before	9,773
Financing Receivable, prior	12,210
Financing Receivable, revolving	104
Pass [Member] | Commercial Portfolio Segment [Member]
Loans receivable	391,602	523,889
Financing Receivable, current year	41,000
Financing Receivable, one year before	150,387
Financing Receivable, two years before	77,204
Financing Receivable, three years before	46,837
Financing Receivable, four years before	4,618
Financing Receivable, prior	2,319
Financing Receivable, revolving	69,237
Pass [Member] | Consumer Portfolio Segment [Member]
Loans receivable	1,340	1,559
Financing Receivable, current year	167
Financing Receivable, one year before	11
Financing Receivable, two years before	146
Financing Receivable, three years before	159
Financing Receivable, four years before	278
Financing Receivable, prior	0
Financing Receivable, revolving	579
Watch [Member]
Loans receivable	34,775	28,584
Watch [Member] | Real Estate Portfolio [Member] | One-to-Four Family Residential Real Estate [Member]
Loans receivable	41	62
Financing Receivable, current year	0
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	41
Financing Receivable, revolving	0
Watch [Member] | Real Estate Portfolio [Member] | Multi-family Mortgage [Member]
Loans receivable	3,510	3,141
Financing Receivable, current year	0
Financing Receivable, one year before	650
Financing Receivable, two years before	0
Financing Receivable, three years before	264
Financing Receivable, four years before	0
Financing Receivable, prior	2,596
Financing Receivable, revolving	0
Watch [Member] | Real Estate Portfolio [Member] | Nonresidential Real Estate [Member]
Loans receivable	4,287	3,070
Financing Receivable, current year	0
Financing Receivable, one year before	2,567
Financing Receivable, two years before	1,547
Financing Receivable, three years before	0
Financing Receivable, four years before	0
Financing Receivable, prior	173
Financing Receivable, revolving	0
Watch [Member] | Commercial Portfolio Segment [Member]
Loans receivable	26,932	22,299
Financing Receivable, current year	4,101
Financing Receivable, one year before	8,114
Financing Receivable, two years before	1,006
Financing Receivable, three years before	353
Financing Receivable, four years before	0
Financing Receivable, prior	0
Financing Receivable, revolving	13,358
Watch [Member] | Consumer Portfolio Segment [Member]
Loans receivable	5	12
Financing Receivable, current year	0
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	5
Special Mention [Member]
Loans receivable	1,338	1,525
Special Mention [Member] | Real Estate Portfolio [Member] | One-to-Four Family Residential Real Estate [Member]
Loans receivable	0	4
Special Mention [Member] | Real Estate Portfolio [Member] | Multi-family Mortgage [Member]
Loans receivable	1,335	0
Special Mention [Member] | Real Estate Portfolio [Member] | Nonresidential Real Estate [Member]
Loans receivable	0	0
Special Mention [Member] | Commercial Portfolio Segment [Member]
Loans receivable	0	1,517
Special Mention [Member] | Commercial Portfolio Segment [Member] | Multi-family Mortgage [Member]
Loans receivable	1,335
Financing Receivable, current year	0
Financing Receivable, one year before	1,335
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
Special Mention [Member] | Consumer Portfolio Segment [Member]
Loans receivable	3	4
Financing Receivable, current year	0
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	3
Substandard [Member]
Loans receivable	5,970	4,372
Substandard [Member] | Real Estate Portfolio [Member] | One-to-Four Family Residential Real Estate [Member]
Loans receivable	282	327
Financing Receivable, current year	0
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	134
Financing Receivable, revolving	148
Substandard [Member] | Real Estate Portfolio [Member] | Multi-family Mortgage [Member]
Loans receivable	0	0
Substandard [Member] | Real Estate Portfolio [Member] | Nonresidential Real Estate [Member]
Loans receivable	0	0
Substandard [Member] | Commercial Portfolio Segment [Member]
Loans receivable	5,685	4,041
Financing Receivable, current year	0
Financing Receivable, one year before	2,143
Financing Receivable, two years before	0
Financing Receivable, three years before	27
Financing Receivable, four years before	0
Financing Receivable, prior	0
Financing Receivable, revolving	3,515
Substandard [Member] | Consumer Portfolio Segment [Member]
Loans receivable	3	4
Financing Receivable, current year	0
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	3
Substandard Nonaccrual [Member]
Loans receivable	23,508	1,407
Substandard Nonaccrual [Member] | Real Estate Portfolio [Member] | One-to-Four Family Residential Real Estate [Member]
Loans receivable	40	92
Financing Receivable, current year	0
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	17
Financing Receivable, revolving	23
Substandard Nonaccrual [Member] | Real Estate Portfolio [Member] | Multi-family Mortgage [Member]
Loans receivable	0	0
Substandard Nonaccrual [Member] | Real Estate Portfolio [Member] | Nonresidential Real Estate [Member]
Loans receivable	0	0
Substandard Nonaccrual [Member] | Commercial Portfolio Segment [Member]
Loans receivable	23,468	1,310
Financing Receivable, current year	11
Financing Receivable, one year before	22,028
Financing Receivable, two years before	540
Financing Receivable, three years before	889
Financing Receivable, four years before	0
Financing Receivable, prior	0
Financing Receivable, revolving	0
Substandard Nonaccrual [Member] | Consumer Portfolio Segment [Member]
Loans receivable	$ 0	$ 5

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

Name:	bfin_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossRecoveryWriteoffNet
Namespace Prefix:	bfin_
Data Type:	xbrli:monetaryItemType
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

Name:	bfin_FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYearRecovery
Namespace Prefix:	bfin_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

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

Name:	bfin_FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYearRecoveryWriteoffNet
Namespace Prefix:	bfin_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Amount, excluding accrued interest, of recovery of financing receivable that can be withdrawn, repaid, and redrawn.

+ References

No definition available.

+ Details

Name:	bfin_FinancingReceivableExcludingAccruedInterestRevolvingRecovery
Namespace Prefix:	bfin_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Amount, excluding accrued interest, of recovery (writeoff) of financing receivable that can be withdrawn, repaid, and redrawn.

+ References

No definition available.

+ Details

Name:	bfin_FinancingReceivableExcludingAccruedInterestRevolvingRecoveryWriteoffNet
Namespace Prefix:	bfin_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

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

Name:	bfin_FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYearRecovery
Namespace Prefix:	bfin_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- 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

Name:	bfin_FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYearRecoveryWriteoffNet
Namespace Prefix:	bfin_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Amount, excluding accrued interest, of recovery of financing receivable originated three years before current fiscal year. Excludes net investment in lease.

+ References

No definition available.

+ Details

Name:	bfin_FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYearRecovery
Namespace Prefix:	bfin_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Amount, excluding accrued interest, of recovery (writeoff) of financing receivable originated three years before current fiscal year. Excludes net investment in lease.

+ References

No definition available.

+ Details

Name:	bfin_FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYearRecoveryWriteoffNet
Namespace Prefix:	bfin_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Amount, excluding accrued interest, of recovery of financing receivable originated in current fiscal year. Excludes net investment in lease.

+ References

No definition available.

+ Details

Name:	bfin_FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYearRecovery
Namespace Prefix:	bfin_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Amount, excluding accrued interest, of recovery (writeoff) of financing receivable originated in current fiscal year. Excludes net investment in lease.

+ References

No definition available.

+ Details

Name:	bfin_FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYearRecoveryWriteoffNet
Namespace Prefix:	bfin_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Amount, excluding accrued interest, of recovery of financing receivable originated two years before current fiscal year. Excludes net investment in lease.

+ References

No definition available.

+ Details

Name:	bfin_FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYearRecovery
Namespace Prefix:	bfin_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Amount, excluding accrued interest, of recovery (writeoff) of financing receivable originated two years before current fiscal year. Excludes net investment in lease.

+ References

No definition available.

+ Details

Name:	bfin_FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYearRecoveryWriteoffNet
Namespace Prefix:	bfin_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Amount, excluding accrued interest, of recovery of financing receivable originated in fiscal year before current fiscal year. Excludes net investment in lease.

+ References

No definition available.

+ Details

Name:	bfin_FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYearRecovery
Namespace Prefix:	bfin_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Amount, excluding accrued interest, of recovery (writeoff) of financing receivable originated in fiscal year before current fiscal year. Excludes net investment in lease.

+ References

No definition available.

+ Details

Name:	bfin_FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYearRecoveryWriteoffNet
Namespace Prefix:	bfin_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Amortized cost, before allowance for credit loss, fee, and loan in process, of financing receivable. Excludes financing receivable covered under loss sharing agreement and net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-5

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481990/310-10-45-2

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(7))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479853/942-210-S99-1

+ Details

Name:	us-gaap_FinancingReceivableBeforeAllowanceForCreditLossAndFee
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Amount, excluding accrued interest, of increase in allowance for credit loss on financing receivable from recovery. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-13

+ Details

Name:	us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossRecovery
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Amount, excluding accrued interest, of decrease in allowance for credit loss on financing receivable from writeoff. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-6

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-13

+ Details

Name:	us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Amount, excluding accrued interest, of writeoff of financing receivable originated more than five years before current fiscal year. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-6

+ Details

Name:	us-gaap_FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYearWriteoff
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Amount, excluding accrued interest, of writeoff of financing receivable that can be withdrawn, repaid, and redrawn.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-6

+ Details

Name:	us-gaap_FinancingReceivableExcludingAccruedInterestRevolvingWriteoff
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Amount, excluding accrued interest, of writeoff of financing receivable originated four years before current fiscal year. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-6

+ Details

Name:	us-gaap_FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYearWriteoff
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Amount, excluding accrued interest, of writeoff of financing receivable originated three years before current fiscal year. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-6

+ Details

Name:	us-gaap_FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYearWriteoff
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Amount, excluding accrued interest, of writeoff of financing receivable originated in current fiscal year. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-6

+ Details

Name:	us-gaap_FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYearWriteoff
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Amount, excluding accrued interest, of writeoff of financing receivable originated two years before current fiscal year. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-6

+ Details

Name:	us-gaap_FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYearWriteoff
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Amount, excluding accrued interest, of writeoff of financing receivable originated in fiscal year before current fiscal year. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-6

+ Details

Name:	us-gaap_FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYearWriteoff
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Amortized cost of financing receivable originated more than five years prior to current fiscal year. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 79
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479294/326-20-55-79

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-6

+ Details

Name:	us-gaap_FinancingReceivableOriginatedFiveOrMoreYearsBeforeLatestFiscalYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Amortized cost of financing receivable originated four years prior to current fiscal year. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 79
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479294/326-20-55-79

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-6

+ Details

Name:	us-gaap_FinancingReceivableOriginatedFourYearsBeforeLatestFiscalYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Amortized cost of financing receivable originated in current fiscal year. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 79
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479294/326-20-55-79

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-6

+ Details

Name:	us-gaap_FinancingReceivableOriginatedInCurrentFiscalYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Amortized cost of financing receivable originated in fiscal year prior to current fiscal year. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 79
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479294/326-20-55-79

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-6

+ Details

Name:	us-gaap_FinancingReceivableOriginatedInFiscalYearBeforeLatestFiscalYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Amortized cost of financing receivable originated three years prior to current fiscal year. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 79
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479294/326-20-55-79

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-6

+ Details

Name:	us-gaap_FinancingReceivableOriginatedThreeYearsBeforeLatestFiscalYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Amortized cost of financing receivable originated two years prior to current fiscal year. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 79
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479294/326-20-55-79

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-6

+ Details

Name:	us-gaap_FinancingReceivableOriginatedTwoYearsBeforeLatestFiscalYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Amortized cost of financing receivable that can be withdrawn, repaid, and redrawn.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 79
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479294/326-20-55-79

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-6

+ Details

Name:	us-gaap_FinancingReceivableRevolving
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=bfin_RealEstatePortfolioMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=bfin_OnetoFourFamilyResidentialRealEstateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=bfin_MultifamilyMortgageMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=bfin_NonresidentialRealEstateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ConsumerPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=us-gaap_PassMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=bfin_WatchMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=us-gaap_SpecialMentionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=us-gaap_SubstandardMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=bfin_SubstandardNonaccrualMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: