Condensed Consolidated Balance Sheets (Unaudited) (USD $)	Jun. 30, 2012	Dec. 31, 2011
Current assets
Cash and cash equivalents	$ 56,049,622	$ 63,077,178
Short-term investments	30,142,552	24,739,998
Total cash, cash equivalents and short-term investments	86,192,174	87,817,176
Accounts receivable, net	10,478,984	9,853,682
Inventories	25,241,532	21,175,754
Other current assets	1,096,392	999,919
Total current assets	123,009,082	119,846,531
Marketable securities and other investments	12,484,167	21,268,777
Property and equipment, net	36,458,792	36,713,578
Other assets	440,135	232,594
Total assets	172,392,176	178,061,480
Current liabilities
Accounts payable	2,831,664	3,476,030
Accrued liabilities	9,951,349	12,437,921
Deferred revenue	4,010,724	4,423,980
Total current liabilities	16,793,737	20,337,931
Accrued income taxes	3,129,577	3,082,356
Total liabilities	19,923,314	23,420,287
Commitments and contingencies (Note 12)
Stockholders' equity
Preferred stock, $0.01 par value- Authorized - 1,500,000 shares Issued - none	0	0
Common stock, $0.01 par value- Authorized - 45,000,000 shares Issued and Outstanding - 19,590,244 and 19,542,677 and 19,573,244 and 19,573,244 shares, respectively	195,903	195,733
Additional paid-in capital	220,482,245	219,062,043
Accumulated other comprehensive loss	(93,120)	(263,849)
Treasury stock, at cost - 47,567 and 0 shares, respectively	0	0
Accumulated deficit	(68,116,166)	(64,352,734)
Total stockholders' equity	152,468,862	154,641,193
Total liabilities and stockholders' equity	$ 172,392,176	$ 178,061,480