Note 5 - Revenues - Contract Assets and Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2022	Jun. 30, 2021
Three months ended June 30, 2022	$ 760	$ 578	$ 701	$ 585	$ 578	$ 585
Unbilled		965		980	1,605	1,565
Three months ended June 30, 2022		(580)		(579)	(1,038)	(1,048)
Three months ended June 30, 2022	1,145	760	1,102	701	1,145	1,102
Balance		3,400			3,400
Billings		580		579	1,038	1,048
Balance	5,800				5,800
Deferred Membership Dues [Member]
Three months ended June 30, 2022	(2,633)		(2,915)		(5,927)	(5,448)
Balance	4,943	3,363	4,122	3,196	3,363	3,196
Billings	2,633		2,915		5,927	5,448
Revenue recognized	(1,794)		(1,661)		(3,508)	(3,268)
Balance	5,782	4,943	5,376	4,122	5,782	5,376
Customer Advance Deposits [Member]
Three months ended June 30, 2022	(915)		(479)		(1,303)	(711)
Balance	920	795	752	674	795	674
Billings	915		479		1,303	711
Revenue recognized	(843)		(447)		(1,106)	(601)
Balance	$ 992	$ 920	$ 784	$ 752	$ 992	$ 784