Note 3 - Contracts With Customers - Information About Receivables, Contract Assets, and Contract Liabilities From Contracts With Customers (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Accounts receivables	$ 15,888		$ 11,922
Deferred Revenue	(18,241)		(16,244)
Revenue recognized that was included in deferred revenue at beginning of year due to completion of services	(7,289)	$ (8,238)
Increases due to invoicing of client, net of amounts recognized as revenue	9,082	8,655
Decreases due to completion of services (or portion of services) and transferred to accounts receivable	(32)	(35)
Change due to cumulative catch-up adjustments arising from changes in expected contract consideration	204	(94)
Increases due to revenue recognized in the period with additional performance obligations before invoicing	79	$ 49
Other Current Assets [Member]
Contract assets included in other current assets	$ 100		$ 53