Condensed Consolidated Balance Sheets (USD $)	Sep. 30, 2013	Dec. 31, 2012
Current Assets:
Cash and cash equivalents	$ 35,005,494	$ 36,126,791
Short-term investments	8,751,409	1,680,958
Accounts and notes receivable, net of allowance of $200,000 as of September 30, 2013 and December 31, 2012	20,093,295	18,101,240
Inventory, net	12,289,360	10,993,209
Prepaid expenses and other current assets	4,859,631	2,754,331
Deferred income tax assets, net	9,450,523	9,395,987
Total current assets	90,449,712	79,052,516
Property and equipment, net	19,347,416	21,952,201
Deferred income tax assets, net	10,397,208	11,605,812
Intangible assets, net	3,360,355	3,317,169
Long-term investments	4,580,049
Other assets	357,512	308,553
Total assets	128,492,252	116,236,251
Current Liabilities:
Accounts payable	5,112,997	6,222,904
Accrued liabilities	8,180,852	7,065,085
Current portion of deferred revenue	6,317,899	4,287,305
Customer deposits	1,077,622	500,018
Current portion of capital lease payable	35,545	33,947
Total current liabilities	20,724,915	18,109,259
Deferred revenue, net of current portion	12,302,510	7,835,767
Liability for unrecorded tax benefits	3,074,447	2,902,896
Other long-term liabilities	169,116
Long-term portion of capital lease payable	76,423	103,283
Total liabilities	36,347,411	28,951,205
Commitments and Contingencies
Stockholders' Equity
Preferred stock, $0.00001 par value per share; 25 million shares authorized; no shares at September 30, 2013 and December 31, 2012
Common stock, $0.00001 par value per share; 200 million shares authorized; 51,838,855 and 52,770,392 shares issued and outstanding at September 30, 2013 and December 31, 2012, respectively	683	661
Additional paid-in capital	128,623,101	111,661,393
Treasury stock at cost, 16,412,755 and 13,363,789 shares at September 30, 2013 and December 31, 2012, respectively	(92,202,810)	(67,203,043)
Retained earnings	55,752,014	42,883,067
Accumulated other comprehensive loss	(28,147)	(57,032)
Total stockholders' equity	92,144,841	87,285,046
Total liabilities and stockholders' equity	$ 128,492,252	$ 116,236,251