Note 2 - Revenue Recognition (Details Textual) - USD ($)	3 Months Ended		9 Months Ended		15 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022
Revenue from Contract with Customer, Excluding Assessed Tax	$ 8,406,000	$ 10,646,000	$ 28,532,000	$ 31,289,000
Contract with Customer, Asset, Credit Loss Expense (Reversal)	0	0	0	0
Capitalized Contract Cost, Amortization	3,000	4,000	12,000	57,000
Capitalized Contract Cost, Impairment Loss	0	0	0	0
Transferred at Point in Time [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	7,700,000		26,900,000	28,400,000	$ 9,600,000
Transferred over Time [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 700,000	$ 1,000,000.0	$ 1,700,000	$ 2,900,000