Condensed Consolidated Balance Sheets (USD $)	Jun. 30, 2013	Dec. 31, 2012
Current Assets:
Cash and cash equivalents	$ 19,079,341	$ 36,126,791
Short-term investments	10,733,249	1,680,958
Accounts and notes receivable, net of allowance of $200,000 as of June 30, 2013 and December 31, 2012	16,889,785	18,101,240
Inventory, net	13,200,436	10,993,209
Prepaid expenses and other current assets	6,579,742	2,754,331
Deferred income tax assets, net	9,395,987	9,395,987
Total current assets	75,878,540	79,052,516
Property and equipment, net	20,032,085	21,952,201
Deferred income tax assets, net	11,686,195	11,605,812
Intangible assets, net	3,332,521	3,317,169
Long-term investments	1,875,723
Other assets	203,122	308,553
Total assets	113,008,186	116,236,251
Current Liabilities:
Accounts payable	5,897,846	6,222,904
Accrued liabilities	7,425,604	7,065,085
Current portion of deferred revenue	5,371,520	4,287,305
Customer deposits	1,235,186	500,018
Current portion of capital lease payable	35,004	33,947
Total current liabilities	19,965,160	18,109,259
Deferred revenue, net of current portion	10,219,802	7,835,767
Liability for unrecorded tax benefits	3,072,863	2,902,896
Long-term portion of capital lease payable	85,515	103,283
Total liabilities	33,343,340	28,951,205
Commitments and Contingencies
Stockholders' Equity
Preferred stock, $0.00001 par value per share; 25 million shares authorized; no shares at June 30, 2013 and December 31, 2012
Common stock, $0.00001 par value per share; 200 million shares authorized; 50,748,873 and 52,770,392 shares issued and outstanding at June 30, 2013 and December 31, 2012, respectively	672	661
Additional paid-in capital	121,349,015	111,661,393
Treasury stock at cost, 16,412,755 and 13,363,789 shares at June 30, 2013 and December 31, 2012, respectively	(92,202,810)	(67,203,043)
Retained earnings	50,638,422	42,883,067
Accumulated other comprehensive loss	(120,453)	(57,032)
Total stockholders' equity	79,664,846	87,285,046
Total liabilities and stockholders' equity	$ 113,008,186	$ 116,236,251