Note 19 - Quarterly Financial Data (Unaudited)

12 Months Ended

Dec. 31, 2013

Quarterly Financial Information Disclosure [Abstract]

Quarterly Financial Information [Text Block]

19. Quarterly Financial Data (Unaudited)

Year 2013	Quarter ended December 31,		Quarter ended September 30,		Quarter ended June 30,		Quarter ended March 31,
Product revenue	$	20,188,488	$	17,023,346	$	20,067,407	$	14,494,489
Total revenue		21,251,328		17,754,438		20,828,377		15,247,011
Cost of product revenue		6,235,334		5,377,568		6,311,332		4,841,170
Gross profit on product revenue		13,953,154		11,645,778		13,756,075		9,653,319
Net income	$	6,654,369	$	4,957,258	$	5,894,892	$	3,068,002
Per common share information:
Basic net income per share	$	0.47	$	0.36	$	0.44	$	0.23
Basic common shares outstanding		14,272,606		13,682,449		13,510,573		13,406,952
Diluted net income per share	$	0.44	$	0.33	$	0.40	$	0.21
Diluted common shares outstanding		15,084,738		14,958,965		14,578,927		14,357,110

Year 2012	Quarter ended December 31,		Quarter ended September 30,		Quarter ended June 30,		Quarter ended March 31,
Product revenue	$	21,459,124	$	14,055,440	$	18,882,277	$	13,613,328
Total revenue		22,606,465		14,766,611		19,624,769		14,360,660
Cost of product revenue		7,269,886		7,221,028		8,084,226		6,413,481
Gross profit on product revenue		14,189,238		6,834,412		10,798,051		7,199,847
Net income	$	4,463,223	$	1,645,250	$	3,736,868	$	1,912,119
Per common share information:
Basic net income per share	$	0.33	$	0.12	$	0.28	$	0.15
Basic common shares outstanding		13,324,942		13,287,463		13,262,023		13,162,824
Diluted net income per share	$	0.31	$	0.11	$	0.26	$	0.14
Diluted common shares outstanding		14,299,211		14,459,154		14,443,794		14,089,946