The length of the contract.

No definition available.

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Namespace Prefix:	ftek_
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Balance Type:	na
Period Type:	duration

- Definition

The number of contracts in progress identified as loss contracts.

+ References

No definition available.

+ Details

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- Definition

The number of units installed.

+ References

No definition available.

+ Details

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- Definition

Amount, after allowance for credit loss, of right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
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+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable, classified as current.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

Amount of revenue recognized that was previously included in balance of obligation to transfer good or service to customer for which consideration from customer has been received or is due.

+ References

+ Details

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Balance Type:	credit
Period Type:	duration

- Definition

Cumulative provision for contract losses not offset against related costs accumulated on the balance sheet.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 605
-SubTopic 35
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-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=123355788&loc=d3e57777-111642

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Balance Type:	credit
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- Definition

Amount of transaction price allocated to performance obligation that has not been recognized as revenue.

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- Details

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Note 3 - Revenue 1 (Details Textual) $ in Thousands	3 Months Ended		9 Months Ended
Note 3 - Revenue 1 (Details Textual) $ in Thousands	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)	Dec. 31, 2020 USD ($)
Number Of Units Installed	1,200		1,200
Contract with Customer, Liability, Current	$ 1,246		$ 1,246		$ 850
Contract with Customer, Liability, Revenue Recognized	$ 173	$ 97	$ 331	$ 555
Contract with Customer, Contracts in Progress, Number of Contracts Identified as Loss Contracts	0		0		1
Provision for Loss on Contracts					$ 176
Revenue, Remaining Performance Obligation, Amount	$ 8,173		$ 8,173
Air Pollution Control [Member]
Contract with Customer, Asset, after Allowance for Credit Loss, Total	375		375		2,080
FUEL CHEM [Member]
Contract with Customer, Asset, after Allowance for Credit Loss, Total	$ 0		$ 0		$ 269
Minimum [Member]
Contract Term (Month)			6 months
Maximum [Member]
Contract Term (Month)			18 months