Note 10 - Segment Reporting (Details Textual)	3 Months Ended
	Mar. 31, 2023 USD ($)	Mar. 31, 2022 USD ($)
Number of Operating Segments	3
Revenue from Contract with Customer, Including Assessed Tax	$ 8,695,000	$ 4,656,000
Intersegment Eliminations [Member]
Revenue from Contract with Customer, Including Assessed Tax	(129,000)	(44,000)
Intersegment Eliminations [Member] | SDC [Member]
Revenue from Contract with Customer, Including Assessed Tax	$ 129,000	$ 44,000