Note 4 - Goodwill and Intangible Assets - Schedule of Future Estimated Amortization Costs of Intangible Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018	[1]
Remaining nine months of 2019	$ 1,311
Year ending December 31, 2020	95
Total	$ 1,406	$ 1,938

[1] Derived from the Company's audited consolidated financial statements as of December 31, 2018.