Note 3 - Contracts With Customers - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenue	$ 147,954	$ 133,277	$ 127,982
Transferred over Time [Member] | Subscription Services [Member]
Revenue	137,008	122,499	114,216
Transferred over Time [Member] | Fixed, Non-subscription Services [Member]
Revenue	3,065	2,907	3,248
Transferred over Time [Member] | Unit Price Services [Member]
Revenue	4,665	4,939	5,526
Transferred at Point in Time [Member] | Service [Member]
Revenue	$ 3,216	$ 2,932	$ 4,992