Note 3 - Loans and Allowance for Loan Losses - Troubled Debt Restructuring by Accrual Status (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Recorded investment in loans	$ 513,668	$ 490,830
Real Estate Mortgage Portfolio Segment [Member] \| Residential Loan [Member]
Recorded investment in loans	138,329	131,152
Real Estate Mortgage Portfolio Segment [Member] \| Commercial Real Estate Loan [Member]
Recorded investment in loans	148,720	138,141
Commercial Portfolio Segment [Member]
Recorded investment in loans	58,173	51,921
Consumer Portfolio Segment [Member] \| Home Equity and Second Mortgage [Member]
Recorded investment in loans	57,207	55,742
Nonperforming Financial Instruments [Member]
TDR accruing	867	975
TDR nonaccrual	286	287
Recorded investment in loans	1,153	1,262
TDR related allowance for loan losses	5	7
Nonperforming Financial Instruments [Member] \| Real Estate Mortgage Portfolio Segment [Member] \| Residential Loan [Member]
TDR accruing	214	216
TDR nonaccrual	0	0
Recorded investment in loans	214	216
TDR related allowance for loan losses	0	0
Nonperforming Financial Instruments [Member] \| Real Estate Mortgage Portfolio Segment [Member] \| Commercial Real Estate Loan [Member]
TDR accruing	486	585
TDR nonaccrual	0	0
Recorded investment in loans	486	585
TDR related allowance for loan losses	0	0
Nonperforming Financial Instruments [Member] \| Commercial Portfolio Segment [Member]
TDR accruing	167	174
TDR nonaccrual	0	0
Recorded investment in loans	167	174
TDR related allowance for loan losses	0	0
Nonperforming Financial Instruments [Member] \| Consumer Portfolio Segment [Member] \| Home Equity and Second Mortgage [Member]
TDR accruing	0	0
TDR nonaccrual	286	287
Recorded investment in loans	286	287
TDR related allowance for loan losses	$ 5	$ 7

Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section S99
-Paragraph 4
-Subparagraph (SAB Topic 6.L.1)
-URI https://asc.fasb.org/extlink&oid=122038336&loc=d3e74567-122707

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (g)
-URI https://asc.fasb.org/extlink&oid=123577603&loc=SL6953423-111524

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (b)(1)(ii)
-URI https://asc.fasb.org/extlink&oid=121614798&loc=d3e15032-111544

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(1)
-URI https://asc.fasb.org/extlink&oid=123577603&loc=SL6953423-111524

+ Details

Name:	us-gaap_LoansAndLeasesReceivableAllowance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI https://asc.fasb.org/extlink&oid=124259787&loc=d3e4428-111522

+ Details

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

- Definition

Reflects the carrying amount of loans deemed to be questionable as to collection on which interest is continuing to be earned or accrued.

+ References

No definition available.

+ Details

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

- Definition

Reflects the carrying amount of loans deemed to be questionable as to collection on which no interest is continuing to be recognized.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=123577603&loc=d3e5111-111524

+ Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

Name:	us-gaap_FinancialInstrumentPerformanceStatusAxis=us-gaap_NonperformingFinancingReceivableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: