Note 11 - Financial Information about Geographic Areas - Consolidated Net Sales and Long-lived Asset Information by Geographic Area (Details) - USD ($)	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Revenues	$ 13,800,000	$ 17,661,000
Reportable Geographical Components [Member]
long-lived assets	5,788,000		$ 5,742,000
UNITED STATES | Reportable Geographical Components [Member]
Revenues	13,694,000	17,076,000
long-lived assets	4,460,000		4,380,000
International Member | Reportable Geographical Components [Member]
Revenues	106,000	$ 585,000
long-lived assets	$ 1,328,000		$ 1,362,000