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Stockholders' Equity (Details Textual) (USD $)
In Millions, except Share data, unless otherwise specified |
3 Months Ended | 6 Months Ended | 3 Months Ended | 6 Months Ended | 3 Months Ended | 6 Months Ended | 3 Months Ended | 6 Months Ended | 3 Months Ended | 6 Months Ended | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
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Jun. 30, 2012
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Jun. 30, 2012
|
Jan. 20, 2012
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Dec. 31, 2011
|
Jun. 30, 2012
August 2008 Offering [Member]
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Dec. 31, 2011
August 2008 Offering [Member]
|
Jun. 30, 2012
October 2009 Offering [Member]
|
Dec. 31, 2011
October 2009 Offering [Member]
|
Jun. 30, 2012
March 2011 Offering [Member]
|
Dec. 31, 2011
March 2011 Offering [Member]
|
Jun. 30, 2012
Warrant [Member]
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Jun. 30, 2012
Warrant [Member]
|
Jun. 30, 2012
Warrant [Member]
August 2008 Offering [Member]
|
Jun. 30, 2012
Warrant [Member]
August 2008 Offering [Member]
|
Jun. 30, 2012
Warrant [Member]
October 2009 Offering [Member]
|
Jun. 30, 2012
Warrant [Member]
October 2009 Offering [Member]
|
Jun. 30, 2012
Warrant [Member]
March 2011 Offering [Member]
|
Jun. 30, 2012
Warrant [Member]
March 2011 Offering [Member]
|
Jun. 30, 2012
Common Stock [Member]
|
Mar. 31, 2012
Common Stock [Member]
|
|
| Stockholders Equity (Textual) [Abstract] | ||||||||||||||||||||
| Common stock having aggregate price of upto | $ 15.0 | |||||||||||||||||||
| Common stock sold, shares | 55,122,594 | 55,122,594 | 49,128,475 | 0 | 2,022,144 | |||||||||||||||
| Common stock sold, price per share | $ 6.29 | |||||||||||||||||||
| Net proceeds from sale of common stock | 12.3 | |||||||||||||||||||
| Warrants outstanding | 3,529,398 | 3,588,221 | 4,706,787 | 7,329,819 | 4,378,940 | 5,725,227 | ||||||||||||||
| Warrants Exercised | 1,011,891 | 3,712,023 | ||||||||||||||||||
| Change in fair value of common stock warrants | 5.2 | 19.5 | 6.9 | 37.6 | 7.7 | 31.5 | ||||||||||||||
| Stockholders Equity (Additional Textual) [Abstract] | ||||||||||||||||||||
| Proceeds from warrant exercises | 2.3 | 6.9 | ||||||||||||||||||
| Reclassification of fair value from liability to permanent equity of warrants exercised | $ 6.0 | $ 22.0 | ||||||||||||||||||