Note 2 - Revenue Recognition (Details Textual) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Revenue from Contract with Customer, Excluding Assessed Tax	$ 9,292,000	$ 8,406,000	$ 23,958,000	$ 28,532,000
Contract with Customer, Asset, Credit Loss Expense (Reversal)	0	0	0	0
Capitalized Contract Cost, Amortization	0	3,000	11,250	12,000
Capitalized Contract Cost, Impairment Loss	0	0	$ 0	0
Minimum [Member]
Customer Payment Terms (Day)			30 days
Maximum [Member]
Customer Payment Terms (Day)			60 days
Transferred at Point in Time [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	8,800,000	7,700,000	$ 22,100,000	26,900,000
Transferred over Time [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 500,000	$ 700,000	$ 1,900,000	$ 1,700,000