Note 12 - Revision of Prior Period Financial Statements (Details Textual) - USD ($)	3 Months Ended			9 Months Ended			12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Revenue from Contract with Customer, Excluding Assessed Tax, Total	$ 10,646,000	$ 10,420,000	$ 14,718,000	$ 31,289,000	$ 36,073,000	$ 43,994,000	$ 59,360,000
Revision of Prior Period, Error Correction, Adjustment [Member]
Revenue from Contract with Customer, Excluding Assessed Tax, Total			77,000			$ 77,000	$ 77,000
Error Related to Recognition of Certain Revenues in Edge to Cloud Segment [Member] | Revision of Prior Period, Error Correction, Adjustment [Member]
Revenue from Contract with Customer, Excluding Assessed Tax, Total			$ (77,000)