OTHER LONG-TERM DEBT (Additional Information) (Detail) - USD ($)	12 Months Ended
Sep. 30, 2016	Sep. 30, 2015
Loan maximum commitment	$ 5,000,000
Loan fixed interest rate	4.00%
Loan Amortization Period	20 years
Loan maturity date	Jul. 27, 2022
Interest Expense, Other Long-term Debt	$ 161,000	$ 176,000
Line Of Credit Facility Principal Amount Outstanding		$ 4,600,000

Principal amount borrowed under the credit facility as of the balance sheet date.

No definition available.

Name:	fsfg_LineOfCreditFacilityPrincipalAmountOutstanding
Namespace Prefix:	fsfg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The period upon which a loan or a group of loans Loan amortization period.

+ References

No definition available.

+ Details

Name:	fsfg_LoanAmortizationPeriod
Namespace Prefix:	fsfg_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of interest expense incurred on long-term debt classified as other, including, but not limited to, interest on long-term notes and amortization of issuance costs.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.8)
-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

+ Details

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

- Definition

Date the credit facility terminates, in CCYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_LineOfCreditFacilityExpirationDate1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

The effective interest rate during the reporting period.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityInterestRateDuringPeriod
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

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