Revolving Line of Credit - Additional Information (Detail) (USD $)	12 Months Ended
Sep. 30, 2014
Line of Credit Facility [Line Items]
Unsecured revolving line of credit	$ 200,000,000
Revolving credit facility, expiration date	Sep. 28, 2016
Revolving credit facility, utilization fees, percentage of total credit facility commitment to exceed	50.00%
Credit facility restrictive covenant, maximum consolidated leverage ratio	3.0
Credit facility restrictive covenant, minimum fixed charge ratio	2.5
Borrowings outstanding	$ 99,000,000
Interest rate of borrowings outstanding	1.285%
Federal Fund Rate
Line of Credit Facility [Line Items]
Debt instrument basis spread on variable rate	0.50%
Libor \| Minimum
Line of Credit Facility [Line Items]
Debt instrument basis spread on variable rate	1.00%
Libor \| Maximum
Line of Credit Facility [Line Items]
Debt instrument basis spread on variable rate	1.625%

Fixed Charge Coverage Ratio, Minimum

No definition available.

Name:	fico_FixedChargeCoverageRatioMinimum
Namespace Prefix:	fico_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

Leverage Ratio Maximum

+ References

No definition available.

+ Details

Name:	fico_LeverageRatioMaximum
Namespace Prefix:	fico_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage of borrowings to total credit facility that if exceeded utilization fees are required to be paid.

+ References

No definition available.

+ Details

Name:	fico_MinimumCreditFacilityUtilizationSubjectToUtilizationFee
Namespace Prefix:	fico_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount borrowed under the credit facility as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

+ Details

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

- 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

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

+ Details

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

- Definition

The effective interest rate at the end of the reporting period.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_LineOfCreditFacilityLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
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