Note 5 - Goodwill and Other Intangible Assets - Goodwill By Reportable Segment (Details) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Beginning Balance	$ 14,404,618	$ 11,505,852
Acquisitions	1,997,174	2,898,766
Adjustments	(169,854)	0
Ending Balance	16,231,938	14,404,618
Commercial Air Handling [Member]
Beginning Balance	478,256	478,256
Acquisitions	0	0
Adjustments	0	0
Ending Balance	478,256	478,256
Industrial and Transportation Products [Member]
Beginning Balance	13,926,362	11,027,596
Acquisitions	1,997,174	2,898,766
Adjustments	(169,854)	0
Ending Balance	$ 15,753,682	$ 13,926,362