Consolidated Balance Sheets (USD $)	Dec. 31, 2011	Dec. 31, 2010
Current assets:
Cash and cash equivalents	$ 21,300,733	$ 42,684,241
Short-term investments	5,108,189	0
Accounts receivable, net of allowance of $450,000 and $200,000 as of December 31, 2011 and 2010, respectively	11,780,135	13,542,535
Inventory	11,484,761	17,815,405
Prepaid expenses and other current assets	2,089,676	1,999,525
Deferred income tax assets, net	9,968,929	6,284,489
Total current assets	61,732,423	82,326,195
Property and equipment, net	26,845,220	35,905,765
Deferred income tax assets, net	12,716,169	13,919,753
Intangible assets, net	3,224,006	3,090,876
Other assets	444,933	944,346
Total assets	104,962,751	136,186,935
Current liabilities:
Accounts payable	4,513,938	4,550,789
Accrued liabilities	7,643,004	3,759,800
Current portion of deferred revenue	3,317,641	3,265,260
Customer deposits	413,314	372,145
Total current liabilities	15,887,897	11,947,994
Deferred revenue, net of current portion	4,636,901	4,392,860
Liability for unrecognized tax benefits	1,982,399	2,281,840
Total liabilities	22,507,197	18,622,694
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, 2011 and 2010
Common stock, $0.00001 par value; 200,000,000 shares authorized; 55,696,608 and 62,621,268 shares issued and outstanding as of December 31, 2011 and 2010, respectively	652	647
Additional paid-in capital	101,597,626	97,122,085
Treasury stock at cost, 9,556,183 and 2,091,600 shares as of December 31, 2011 and 2010, respectively	(47,207,093)	(14,708,237)
Retained earnings	28,145,325	35,185,191
Accumulated other comprehensive loss	(80,956)	(35,445)
Total stockholders' equity	82,455,554	117,564,241
Total liabilities and stockholders' equity	$ 104,962,751	$ 136,186,935