Note 8 - Revenue (Details Textual) - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2022	Dec. 31, 2021
Contract with Customer, Liability, Revenue Recognized	$ 144,000	$ 620,000
Contract with Customer, Liability, Current	841,000	841,000	$ 719,000
Contract with Customer, Liability, Noncurrent	$ 1,014,000	$ 1,014,000	$ 1,244,000