Note 16 - Segment and Geographic Information - Total Revenue by Geographic Location (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Total Revenue	$ 27,184	$ 25,789	$ 84,032	$ 74,653
Percentage of Revenue	100.00%	100.00%	100.00%	100.00%
UNITED STATES
Total Revenue	$ 22,227	$ 21,126	$ 68,624	$ 61,032
Percentage of Revenue	82.00%	82.00%	82.00%	82.00%
Europe [Member]
Total Revenue	$ 2,832	$ 2,703	$ 9,743	$ 8,240
Percentage of Revenue	10.00%	10.00%	11.00%	11.00%
Other Location [Member]
Total Revenue	$ 2,125	$ 1,960	$ 5,665	$ 5,381
Percentage of Revenue	8.00%	8.00%	7.00%	7.00%