XML 68 R62.htm IDEA: XBRL DOCUMENT v3.25.3

Loans, Lease Receivables, and Allowance for Credit Losses - Schedule of Amortized Cost Basis of Loans That Had Payment Default (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
Principal Forgiveness
Financing Receivable, Modified, Subsequent Default [Line Items]
Financing Receivable, Excluding Accrued Interest, Modified, Subsequent Default	$ 0	$ 0
Payment Delay
Financing Receivable, Modified, Subsequent Default [Line Items]
Financing Receivable, Excluding Accrued Interest, Modified, Subsequent Default	0	753
Term Extension
Financing Receivable, Modified, Subsequent Default [Line Items]
Financing Receivable, Excluding Accrued Interest, Modified, Subsequent Default	397	0
Interest Rate Reduction
Financing Receivable, Modified, Subsequent Default [Line Items]
Financing Receivable, Excluding Accrued Interest, Modified, Subsequent Default	0	0
Commercial and Industrial | Principal Forgiveness
Financing Receivable, Modified, Subsequent Default [Line Items]
Financing Receivable, Excluding Accrued Interest, Modified, Subsequent Default	0	0
Commercial and Industrial | Payment Delay
Financing Receivable, Modified, Subsequent Default [Line Items]
Financing Receivable, Excluding Accrued Interest, Modified, Subsequent Default	0	753
Commercial and Industrial | Term Extension
Financing Receivable, Modified, Subsequent Default [Line Items]
Financing Receivable, Excluding Accrued Interest, Modified, Subsequent Default	397	0
Commercial and Industrial | Interest Rate Reduction
Financing Receivable, Modified, Subsequent Default [Line Items]
Financing Receivable, Excluding Accrued Interest, Modified, Subsequent Default	0	0
Commercial Real Estate | Principal Forgiveness
Financing Receivable, Modified, Subsequent Default [Line Items]
Financing Receivable, Excluding Accrued Interest, Modified, Subsequent Default	0	0
Commercial Real Estate | Payment Delay
Financing Receivable, Modified, Subsequent Default [Line Items]
Financing Receivable, Excluding Accrued Interest, Modified, Subsequent Default	0	0
Commercial Real Estate | Term Extension
Financing Receivable, Modified, Subsequent Default [Line Items]
Financing Receivable, Excluding Accrued Interest, Modified, Subsequent Default	0	0
Commercial Real Estate | Interest Rate Reduction
Financing Receivable, Modified, Subsequent Default [Line Items]
Financing Receivable, Excluding Accrued Interest, Modified, Subsequent Default	$ 0	$ 0

X

- Definition

Amortized cost excluding accrued interest, of financing receivable with payment default in current period and modified within previous 12 months preceding payment default for debtor experiencing financial difficulty.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 44
-Subparagraph (a)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-44

+ Details

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

X

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 12A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481933/310-10-55-12A

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 44
-Subparagraph (a)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-44

+ Details

Name:	us-gaap_FinancingReceivableModifiedSubsequentDefaultLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_LoanRestructuringModificationAxis=us-gaap_PrincipalForgivenessMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_LoanRestructuringModificationAxis=us-gaap_PaymentDeferralMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_LoanRestructuringModificationAxis=us-gaap_ExtendedMaturityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_LoanRestructuringModificationAxis=us-gaap_InterestRateBelowMarketReductionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

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

X

- Details

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