Note 15 - Subsequent Events (Details Textual) - Subsequent Event [Member] - Restricted Stock Units (RSUs) [Member] $ in Millions	Apr. 06, 2022 USD ($)
Share-Based Compensation Arrangement by Share-Based Payment Award, Minimum Operating Income	$ 1
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)	3 years
Share-Based Compensation Arrangement by Share-Based Payment Award, Commencing Period After Grant Date (Year)	1 year
Share-Based Payment Arrangement, Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage	33.33%
Share-Based Payment Arrangement, Tranche Two [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage	33.33%
Share-Based Payment Arrangement, Tranche Three [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage	33.33%

Represents commencing period after grant date for share-based compensation arrangement by share-based payment award.

No definition available.

Name:	ftek_SharebasedCompensationArrangementBySharebasedPaymentAwardCommencingPeriodAfterGrantDate
Namespace Prefix:	ftek_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents minimum operating income for share-based compensation arrangement by share-based payment award.

+ References

No definition available.

+ Details

Name:	ftek_SharebasedCompensationArrangementBySharebasedPaymentAwardMinimumOperatingIncome
Namespace Prefix:	ftek_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of vesting of award under share-based payment arrangement.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901

+ Details

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

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_RestrictedStockUnitsRSUMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VestingAxis=us-gaap_ShareBasedCompensationAwardTrancheOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VestingAxis=us-gaap_ShareBasedCompensationAwardTrancheTwoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VestingAxis=us-gaap_ShareBasedCompensationAwardTrancheThreeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: