Note 4 - Other Accrued Liabilities - Other Accrued Liabilities (Details) - USD ($)	Sep. 30, 2022	Dec. 31, 2021
Equipment maintenance and upgrades	$ 0	$ 367,000
Insurance	0	340,000
Professional services	116,000	90,000
Operating costs	702,000	397,000
Other	304,000	311,000
Total other accrued liabilities	$ 1,122,000	$ 1,505,000