Consolidated Balance Sheets (USD $)	Dec. 31, 2012	Dec. 31, 2011
Assets
Cash and cash equivalents	$ 55,116,328	$ 63,077,178
Short-term investments	33,057,835	24,739,998
Total cash, cash equivalents and short-term investments	88,174,163	87,817,176
Accounts receivable, net of allowance of $988,707 and $796,610, respectively	10,558,667	9,853,682
Inventories	21,584,907	21,175,754
Other current assets	667,534	999,919
Total current assets	120,985,271	119,846,531
Marketable securities and other investments	11,533,090	21,268,777
Property and equipment, net	35,885,028	36,713,578
Other assets	425,293	232,594
Total assets	168,828,682	178,061,480
Liabilities:
Accounts payable	1,645,696	3,476,030
Accrued liabilities	9,102,544	12,437,921
Deferred revenue	3,286,422	3,746,140
Total current liabilities	14,034,662	19,660,091
Accrued income taxes	3,256,088	3,082,356
Deferred revenue, net of current portion	972,918	677,840
Total liabilities	18,263,668	23,420,287
Commitments and contingencies (Note 6)
Stockholders' equity:
Preferred stock, $.01 par value- Authorized - 1,500,000 shares Issued - none	0	0
Common stock, $.01 par value- Authorized - 45,000,000 - Issued and outstanding - 2012: 19,970,424 and 19,966,149 shares and 2011: 19,573,244 and 19,573,244 shares, respectively	199,705	195,733
Additional paid-in capital	221,180,420	219,062,043
Accumulated other comprehensive loss	(252,891)	(263,849)
Accumulated deficit	(70,523,893)	(64,352,734)
Treasury stock, at cost - 4,275 and 0 shares, respectively	(38,327)	0
Total stockholders' equity	150,565,014	154,641,193
Total liabilities and stockholders' equity	$ 168,828,682	$ 178,061,480