Note 5 - Revenues - Contract Assets and Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Balance at beginning of period	$ 1,083	$ 1,145	$ 599	$ 578
Balance at beginning of period			3,600
Unbilled membership dues	222	252	1,692	1,857
Billings	492	519	1,478	1,557
Billings	(492)	(519)	(1,478)	(1,557)
Balance at end of period	813	878	813	878
Balance at end of period	4,600		4,600
Deferred Membership Dues [Member]
Balance at beginning of period	5,737	5,782	3,643	3,363
Billings	1,031	650	7,653	6,577
Billings	(1,031)	(650)	(7,653)	(6,577)
Revenue recognized	(2,150)	(1,783)	(6,678)	(5,291)
Balance at end of period	4,618	4,649	4,618	4,649
Customer Advance Deposits [Member]
Balance at beginning of period	1,149	992	965	795
Billings	721	785	2,127	2,088
Billings	(721)	(785)	(2,127)	(2,088)
Revenue recognized	(820)	(773)	(2,042)	(1,879)
Balance at end of period	$ 1,050	$ 1,004	$ 1,050	$ 1,004