Note 12 - Revision of Prior Period Financial Statements - Error Correction and Prior Period Adjustments (Details) - USD ($) $ / shares in Units, $ in Thousands	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	Jun. 30, 2021	Dec. 31, 2020
Deferred revenue, current portion	$ 1,098			$ 1,098			$ 1,482		$ 2,088
Total current liabilities	8,830			8,830			11,123		11,262
Accumulated deficit	(131,468)		$ (126,757)	(131,468)		$ (126,757)	(128,117)		(130,006)
Total shareholders' equity	39,836			39,836			9,773	$ 8,886	8,728
Net loss	(895)	$ (136)	(1,030)	(1,462)	$ (1,683)	(7,744)	(9,104)
Total revenue	10,646	10,420	14,718	31,289	36,073	43,994	59,360
Gross profit	1,328	1,890	2,709	4,113	5,521	7,523	10,173
Loss from operations	(866)	(138)	(1,052)	(3,037)	(1,652)	(7,860)	(9,237)
Loss before income taxes	(895)	(136)	(1,030)	(1,462)	(1,683)	(7,744)	(9,088)
Net loss	$ (895)	$ (136)	$ (1,030)	$ (1,462)	$ (1,683)	$ (7,744)	$ (9,104)
Basic loss per share (in dollars per share)	$ (0.05)	$ (0.01)	$ (0.08)	$ (0.09)	$ (0.13)	$ (0.60)	$ (0.71)
Diluted loss per share (in dollars per share)	$ (0.05)	$ (0.01)	$ (0.08)	$ (0.09)	$ (0.13)	$ (0.60)	$ (0.71)
Comprehensive loss	$ (858)	$ (128)	$ (1,034)	$ (1,492)	$ (1,713)	$ (7,822)	$ (9,165)
Deferred revenue				(771)	(310)	(125)	(304)
Net cash used by operating activities				(3,192)	754	(4,994)	(5,995)
Edge to Cloud [Member]
Total revenue	1,008	1,275	2,162	2,896	2,913	6,653	8,732
Gross profit	$ 181	$ 147		$ 248	$ (137)
Previously Reported [Member]
Deferred revenue, current portion							1,559		2,165
Total current liabilities							11,200		11,339
Accumulated deficit			(126,834)			(126,834)	(128,194)		(130,083)
Total shareholders' equity							9,696		8,651
Net loss			(1,107)			(7,821)	(9,181)
Total revenue			14,641			43,917	59,283
Gross profit			2,632			7,446	10,096
Loss from operations			(1,129)			(7,937)	(9,314)
Loss before income taxes			(1,107)			(7,821)	(9,165)
Net loss			$ (1,107)			$ (7,821)	$ (9,181)
Basic loss per share (in dollars per share)			$ (0.09)			$ (0.60)	$ (0.71)
Diluted loss per share (in dollars per share)			$ (0.09)			$ (0.60)	$ (0.71)
Comprehensive loss			$ (1,111)			$ (7,899)	$ (9,242)
Deferred revenue						(48)	(227)
Net cash used by operating activities						(4,994)	(5,995)
Previously Reported [Member] | Edge to Cloud [Member]
Total revenue			2,085			6,576	8,655
Revision of Prior Period, Error Correction, Adjustment [Member]
Deferred revenue, current portion							(77)		(77)
Total current liabilities							(77)		(77)
Accumulated deficit			77			77	77		77
Total shareholders' equity							77		$ 77
Net loss			77			77	77
Total revenue			77			77	77
Gross profit			77			77	77
Loss from operations			77			77	77
Loss before income taxes			77			77	77
Net loss			$ 77			$ 77	$ 77
Basic loss per share (in dollars per share)			$ 0.01			$ 0	$ 0
Diluted loss per share (in dollars per share)			$ 0.01			$ 0	$ 0
Comprehensive loss			$ 77			$ 77	$ 77
Deferred revenue						(77)	(77)
Net cash used by operating activities						0	0
Revision of Prior Period, Error Correction, Adjustment [Member] | Edge to Cloud [Member]
Total revenue			$ 77			$ 77	$ 77