Consolidated Balance Sheets (USD $)	Dec. 31, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 36,126,791	$ 21,300,733
Short-term investments	1,680,958	5,108,189
Accounts and notes receivable, net of allowance of $200,000 and $450,000 as of December 31, 2012 and 2011, respectively	18,101,240	11,780,135
Inventory, net	10,993,209	11,484,761
Prepaid expenses and other current assets	2,754,331	2,089,676
Deferred income tax assets, net	9,395,987	9,968,929
Total current assets	79,052,516	61,732,423
Property and equipment, net	21,952,201	26,845,220
Deferred income tax assets, net	11,605,812	12,716,169
Intangible assets, net	3,317,169	3,224,006
Other assets	308,553	444,933
Total assets	116,236,251	104,962,751
Current liabilities:
Accounts payable	6,222,904	4,513,938
Accrued liabilities	7,065,085	7,643,004
Current portion of deferred revenue	4,287,305	3,317,641
Customer deposits	500,018	413,314
Current portion of capital lease payable	33,947
Total current liabilities	18,109,259	15,887,897
Deferred revenue, net of current portion	7,835,767	4,636,901
Liability for unrecognized tax benefits	2,902,896	1,982,399
Long-term portion of capital lease payable	103,283
Total liabilities	28,951,205	22,507,197
Commitments and contingencies
Stockholders' equity:
Preferred stock, $0.00001 par value; 25,000,000 shares authorized; no shares issued and outstanding as of December 31, 2012 and 2011
Common stock, $0.00001 par value; 200,000,000 shares authorized; 52,770,392 and 55,696,608 shares issued and outstanding as of December 31, 2012 and 2011, respectively	661	652
Additional paid-in capital	111,661,393	101,597,626
Treasury stock at cost, 13,363,789 and 9,556,183 shares as of December 31, 2012 and 2011, respectively	(67,203,043)	(47,207,093)
Retained earnings	42,883,067	28,145,325
Accumulated other comprehensive loss	(57,032)	(80,956)
Total stockholders' equity	87,285,046	82,455,554
Total liabilities and stockholders' equity	$ 116,236,251	$ 104,962,751