Note 14 - Operating Segments - Geographic Segments (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenue	$ 77,786	$ 79,377	$ 74,509	$ 73,042	$ 72,095	$ 75,526	$ 72,822	$ 64,856	$ 304,714	$ 285,299	$ 211,955
Long-lived assets	108,729				94,639				108,729	94,639	87,909
UNITED STATES
Revenue									258,691	255,256	181,743
Long-lived assets	89,597				80,617				89,597	80,617	79,301
Non-US [Member]
Revenue									46,023	30,043	30,212
Long-lived assets	$ 19,132				$ 14,022				$ 19,132	$ 14,022	$ 8,608