Note 5 - Revenues - Contract Assets and Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Balance at beginning of period	$ 567	$ 599
Balance at beginning of period	3,400
Unbilled membership dues	670	620
Billings	(447)	(472)
Balance at end of period	790	747
Balance at end of period	5,200
Deferred Membership Dues [Member]
Balance at beginning of period	3,443	3,643
Billings	3,689	3,104
Revenue recognized	(1,974)	(1,847)
Balance at end of period	5,158	4,900
Customer Advance Deposits [Member]
Balance at beginning of period	1,223	965
Billings	483	757
Revenue recognized	(395)	(640)
Balance at end of period	$ 1,311	$ 1,082