Note 14 - Segment and Geographic Information - Product Revenue by Geographic Location (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
UNITED STATES
Total Revenue	$ 19,239,247	$ 18,455,167	$ 51,048,132	$ 72,935,722
Percentage of Revenue	81.00%	84.00%	82.00%	89.00%
Europe [Member]
Total Revenue	$ 1,976,751	$ 1,784,414	$ 6,293,965	$ 5,274,071
Percentage of Revenue	8.00%	8.00%	10.00%	6.00%
Other Location [Member]
Total Revenue	$ 2,465,259	$ 1,815,842	$ 4,763,045	$ 4,130,577
Percentage of Revenue	11.00%	8.00%	8.00%	5.00%
Total Revenue	$ 23,681,257	$ 22,055,423	$ 62,105,142	$ 82,340,370
Percentage of Revenue	100.00%	100.00%	100.00%	100.00%