Note 2 - Contracts With Customers - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenue	$ 31,166	$ 31,414	$ 65,026	$ 62,894
Transferred over Time [Member] | Subscription Services [Member]
Revenue	29,572	27,918	59,993	55,831
Transferred over Time [Member] | Fixed, Non-subscription Services [Member]
Revenue	158	506	675	1,040
Transferred over Time [Member] | Unit Price Services [Member]
Revenue	1,245	1,365	3,071	3,398
Transferred at Point in Time [Member] | Service [Member]
Revenue	$ 191	$ 1,625	$ 1,287	$ 2,625