XML 116 R102.htm IDEA: XBRL DOCUMENT
v3.24.0.1

Employee Benefit Plan (Details) - USD ($) | 12 Months Ended
--- | ---
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
Retirement Benefits [Abstract] |  |  |
Defined contribution maximum annual matching contribution per employee, percent | 3.00% |  |
Defined contribution maximum annual discretionary contribution per employee, percent | 6.00% |  |
Defined contribution plan, employer matching contribution, percent | 3.00% |  |
Defined contribution plan employer matching contribution | $ 1,200,000 | $ 1,100,000 | $ 987,000
Defined contribution plan employer discretionary contribution percent | 5.90% | 5.20% | 4.70%
Defined contribution plan, employer discretionary contribution amount | $ 2,100,000 | $ 1,600,000 | $ 1,300,000
Deferred compensation plan compensation expense | 493,000 | 382,000 | $ 237,000
Present value of future payments under the remaining deferred compensation plan liability | $ 2,800,000 | $ 2,300,000 |

X
- Definition Defined Contribution Maximum Annual Discretionary Contribution Per Employee, Percent + References No definition available. + Details
Name: | fbiz_DefinedContributionMaximumAnnualDiscretionaryContributionPerEmployeePercent
Namespace Prefix: | fbiz_
Data Type: | dtr-types1:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Defined Contribution Maximum Annual Matching Contribution Per Employee, Percent + References No definition available. + Details
Name: | fbiz_DefinedContributionMaximumAnnualMatchingContributionPerEmployeePercent
Namespace Prefix: | fbiz_
Data Type: | dtr-types1:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Defined Contribution Plan Employer Discretionary Contribution Percent + References No definition available. + Details
Name: | fbiz_DefinedContributionPlanEmployerDiscretionaryContributionPercent
Namespace Prefix: | fbiz_
Data Type: | dtr-types1:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Defined Contribution Plan Employer Matching Contribution, Amount + References No definition available. + Details
Name: | fbiz_DefinedContributionPlanEmployerMatchingContribution
Namespace Prefix: | fbiz_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_CompensationAndRetirementDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The compensation expense recognized during the period pertaining to the deferred compensation arrangement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 710 -SubTopic 10 -Name Accounting Standards Codification -Section 30 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483043/710-10-30-1 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480429/718-10-50-1 + Details
Name: | us-gaap_DeferredCompensationArrangementWithIndividualCompensationExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Aggregate carrying value as of the balance sheet date of the liabilities for deferred compensation arrangements. Represents currently earned compensation under cash arrangements (such as a profit-sharing plan, rabbi trust, and employee contract--excluding equity-based arrangements) that is not actually paid until a later date. + References No definition available. + Details
Name: | us-gaap_DeferredCompensationCashbasedArrangementsLiabilityCurrentAndNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of discretionary contributions made by an employer to a defined contribution plan. + References No definition available. + Details
Name: | us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan. + References No definition available. + Details
Name: | us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration