Note 1 - General (Details Textual) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2025	Jun. 30, 2025	Jun. 30, 2024	Dec. 31, 2024
Employee Retention Credit Receivable	$ 511	$ 511		$ 1,677
Increase (Decrease) Employee Retention Credit Receivable	1,232	$ (1,232)	$ 1,677
Employee Retention Credit Benefit	$ 67

Represents the increase (decrease) in employee retention credit receivable.

No definition available.

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