Note 5 - Assets Held for Rent - Assets Held for Rent (Details)	12 Months Ended
	Dec. 31, 2019 USD ($)
Shippers placed in service	$ 3,073,000
Accumulated depreciation	(174,000)
Net	2,899,000
Shippers and related components in production	1,023,000
Total	$ 3,922,000