Note 5 - Assets Held for Rent (Details Textual) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Assets Held for Rent, Depreciation	$ 410,000	$ 186,000	$ 873,000	$ 581,000