Note 9 - Debt (Details Textual) - ABL Credit Facility [Member] - Secured Debt [Member] - USD ($) $ in Thousands	Nov. 05, 2018	Jun. 30, 2021
Revolving Credit Facility [Member]
Line of Credit Facility, Expiration Period (Year)	5 years
Line of Credit Facility, Maximum Borrowing Capacity	$ 100,000
Line of Credit Facility, Maximum Borrowing Capacity, Potential Increase	$ 200,000
Federal Funds Effective Rate, Interest Rate Floor	0.00%
Debt Instrument, Covenant, Fixed Charge Coverage Ratio	1.0
Line Of Credit Facility, Covenant Terms, Triggering Event, Remaining Borrowing Capacity, Threshold Consecutive Days	2
Line of Credit Facility, Covenant Term, Minimum Fixed Charges	$ 12,500
Line of Credit Facility, Covenant Term, Minimum Fixed Charges, Percentage	15.00%
Line Of Credit Facility, Covenant Terms, Post Triggering Event, Remaining Borrowing Capacity, Threshold Consecutive Days	30
Long-term Line of Credit, Total		$ 0
Letters of Credit Outstanding, Amount		9,400
Line of Credit Facility, Remaining Borrowing Capacity		$ 34,000
Revolving Credit Facility [Member] \| Minimum [Member]
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage	0.25%
Revolving Credit Facility [Member] \| Maximum [Member]
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage	0.375%
Revolving Credit Facility [Member] \| Fed Funds Effective Rate Overnight Index Swap Rate [Member]
Debt Instrument, Basis Spread on Variable Rate	0.50%
Revolving Credit Facility [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument, Basis Spread on Variable Rate	1.00%
Revolving Credit Facility [Member] \| Alternate Base Rate [Member] \| Minimum [Member]
Debt Instrument, Additional Basis Spread on Variable Rate	1.00%
Revolving Credit Facility [Member] \| Alternate Base Rate [Member] \| Maximum [Member]
Debt Instrument, Additional Basis Spread on Variable Rate	1.50%
Revolving Credit Facility [Member] \| Eurodollar [Member] \| Minimum [Member]
Debt Instrument, Basis Spread on Variable Rate	2.00%
Revolving Credit Facility [Member] \| Eurodollar [Member] \| Maximum [Member]
Debt Instrument, Basis Spread on Variable Rate	2.50%
Letter of Credit [Member]
Line of Credit Facility, Maximum Borrowing Capacity	$ 15,000

Represents the additional basis spread on variable rate.

No definition available.

Name:	fi_DebtInstrumentAdditionalBasisSpreadOnVariableRate
Namespace Prefix:	fi_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Requirement for fixed charge coverage ratio under the debt agreement, based one the ratio of (a) consolidated EBITDA minus unfinanced capital expenditures to (b) fixed charges.

+ References

No definition available.

+ Details

Name:	fi_DebtInstrumentCovenantFixedChargeCoverageRatio
Namespace Prefix:	fi_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the interest rate floor associated with the federal funds effective rate.

+ References

No definition available.

+ Details

Name:	fi_FederalFundsEffectiveRateInterestRateFloor
Namespace Prefix:	fi_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the minimum fixed charges amount under a debt instrument covenant.

+ References

No definition available.

+ Details

Name:	fi_LineOfCreditFacilityCovenantTermMinimumFixedCharges
Namespace Prefix:	fi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Represents the minimum fixed charges percentage under a debt instrument covenant.

+ References

No definition available.

+ Details

Name:	fi_LineOfCreditFacilityCovenantTermMinimumFixedChargesPercentage
Namespace Prefix:	fi_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

With regard to a debt instrument covenant, this element represents availability under facility, post triggering event, consecutive number of days.

+ References

No definition available.

+ Details

Name:	fi_LineOfCreditFacilityCovenantTermsPostTriggeringEventRemainingBorrowingCapacityThresholdConsecutiveDays
Namespace Prefix:	fi_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

With regard to a debt instrument covenant, this element represents the availability under facility, triggering event, consecutive number of days (at least).

+ References

No definition available.

+ Details

Name:	fi_LineOfCreditFacilityCovenantTermsTriggeringEventRemainingBorrowingCapacityThresholdConsecutiveDays
Namespace Prefix:	fi_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the amount by which the maximum borrowing capacity may be increased under a line of credit facility.

+ References

No definition available.

+ Details

Name:	fi_LineOfCreditFacilityMaximumBorrowingCapacityPotentialIncrease
Namespace Prefix:	fi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- 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:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

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

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

+ Details

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

- Definition

Period remaining on line of credit facility before it terminates, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_LineOfCreditFacilityExpirationPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
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

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

+ Details

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

- Definition

The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

+ References

No definition available.

+ Details

Name:	us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_DebtInstrumentAxis=fi_ABLCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_SecuredDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_FederalFundsEffectiveSwapRateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=fi_AlternateBaseRateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_EurodollarMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_LetterOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: