Condensed Consolidated Statements Of Operations (USD $)
In Thousands, except Share data, unless otherwise specified
 3 Months Ended 9 Months Ended 12 Months Ended
Sep. 30, 2011
Sep. 30, 2010
Sep. 30, 2011
Sep. 30, 2010
Dec. 31, 2010
Dec. 31, 2009
Dec. 31, 2008
Revenue:              
Product $ 6,306 $ 6,936 $ 16,564 $ 17,826 $ 23,596 $ 19,775 $ 15,730
Contract 1,957 1,320 4,589 4,669 6,862 4,047 3,009
Total revenue, net 8,263 8,256 21,153 22,495 30,458 23,822 18,739
Cost of goods sold:              
Product 2,902 2,105 8,554 6,590 8,373 7,865 9,086
Contract 1,002 683 2,368 2,380 3,645 2,310 1,587
Total Cost of goods sold 3,904 2,788 10,922 8,970 12,018 10,175 10,673
Gross profit 4,359 5,468 10,231 13,525 18,440 13,647 8,066
Operating expenses:              
Research and development 765 511 2,071 1,888 2,370 1,996 2,081
Selling, general and administrative 1,992 2,054 6,361 6,873 10,055 6,900 6,254
Total operating expenses 2,757 2,565 8,432 8,761 12,425 8,896 8,335
Income (loss) from operations 1,602 2,903 1,799 4,764 6,015 4,751 (269)
Other income (expense):              
Interest expense (26) (21) (85) (79) (115) (466) (1,990)
Interest income 3 2 32 10      
Change in fair value of warrant liability 3,028 723 2,548 (9,620) (15,987) (6,533)  
Other income, net         16 67 400
Total other income (expense), net 3,005 704 2,495 (9,689) (16,086) (6,932) (1,590)
Income (loss) before provision for income taxes 4,607 3,607 4,294 (4,925) (10,071) (2,181) (1,859)
Provision for income tax (benefit) expense 488 56 542 75 (8,931) 90  
Net loss (income) $ 4,119 $ 3,551 $ 3,752 $ (5,000) $ (1,140) $ (2,271) $ (1,859)
Loss (income) per common share, basic $ 0.13 $ 0.13 $ 0.13 $ (0.27) $ (0.06) $ (0.14) $ (0.13)
Loss (income) per common share, diluted $ 0.03 $ 0.08 $ 0.02 $ (0.27) $ (0.06) $ (0.14) $ (0.13)
Weighted average number of shares outstanding:              
Basic 23,084,229 19,883,029 22,153,525 18,781,185 19,239,933 16,343,650 14,175,220
Diluted 25,322,920 24,244,477 25,642,105 18,781,185 19,239,933 16,343,650 14,175,220