Note 3 - Contracts With Customers - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Revenue	$ 37,767	$ 33,477	$ 109,656	$ 98,503
Transferred over Time [Member] | Subscription Services [Member]
Revenue	34,598	30,712	101,867	90,101
Transferred over Time [Member] | Fixed, Non-subscription Services [Member]
Revenue	888	460	2,014	1,740
Transferred over Time [Member] | Unit Price Services [Member]
Revenue	1,121	1,135	3,729	4,206
Transferred at Point in Time [Member] | Service [Member]
Revenue	$ 1,160	$ 1,170	$ 2,046	$ 2,456