Note 2 - Revenue Recognition - Significant Changes in Contract Assets and Deferred Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Receivables	$ 3,985	$ 4,914
Short-term contract assets	0	46
Short-term contract liabilities (deferred revenue)	201	944
Long-term contract liabilities (deferred revenue)	9	194
Balance at beginning of period	46	456
Revenue recognized	49	181
Amounts invoiced	(45)	(135)
Reclassifications and other	(50)	(456)
Balance at end of period	0	46
Balance at beginning of period	1,138	2,116
Revenue recognized	(1,495)	(1,977)
Amounts invoiced	617	999
Reclassifications and other	(50)	0
Balance at end of period	$ 210	$ 1,138