Note 5 - Revenues - Contract Assets and Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Balance at beginning of period	$ 790	$ 747	$ 567	$ 599
Balance at beginning of period			3,400
Unbilled membership dues	858	849	1,528	1,470
Billings	(538)	(513)	(985)	(986)
Balance at end of period	1,110	1,083	1,110	1,083
Balance at end of period	5,900		5,900
Deferred Membership Dues [Member]
Balance at beginning of period	5,158	4,900	3,443	3,643
Billings	2,544	2,671	6,233	5,775
Revenue recognized	(1,839)	(1,833)	(3,813)	(3,680)
Balance at end of period	5,863	5,738	5,863	5,738
Customer Advance Deposits [Member]
Balance at beginning of period	1,311	1,082	1,223	965
Billings	726	701	1,209	1,077
Revenue recognized	(725)	(634)	(1,120)	(893)
Balance at end of period	$ 1,312	$ 1,149	$ 1,312	$ 1,149