Note 17 - Geographic Revenue and Long-lived Assets Distribution - Revenue and Long-lived Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue by geographic area	$ 59,753	$ 54,733	$ 46,988
Long-lived assets by geographic area	7,144	2,764
UNITED STATES
Revenue by geographic area	16,442	15,720	10,372
Long-lived assets by geographic area	1,685	1,071
UNITED KINGDOM
Revenue by geographic area	3,626	3,041	2,620
Long-lived assets by geographic area	5,248	1,487
Europe and ROW, Excluding U.K. [Member]
Revenue by geographic area	5,527	5,095	4,368
Long-lived assets by geographic area	101	132
European Union [Member]
Revenue by geographic area	9,153	8,136	6,988
Long-lived assets by geographic area	5,349	1,619
Asia [Member]
Revenue by geographic area	34,158	30,877	$ 29,628
Long-lived assets by geographic area	$ 110	$ 74