Note 5 - Assets Held for Rent - Assets Held for Rent (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Shippers placed in service	$ 6,032	$ 5,645
Fixed assets held for rent	4,686	4,040
Accumulated depreciation	(3,070)	(2,272)
Net	7,648	7,413
Shippers and related components in production	2,175	2,396
Total	$ 9,823	$ 9,809