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Common Stock Options, Warrants And Changes In Capitalization (Details) (USD $) In Thousands, except Share data, unless otherwise specified | 0 Months Ended | 12 Months Ended |  | 1 Months Ended |  | 0 Months Ended |  | 96 Months Ended |  |
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Dec. 24, 2012 | Dec. 31, 2012 | Dec. 31, 2011 | Dec. 31, 2010 | Mar. 31, 2012 | Mar. 31, 2002 Private Placement [Member] | Dec. 31, 2012 Private Placement [Member] | Dec. 24, 2012 Common Stock [Member] Public Offering [Member] | Dec. 05, 2011 Common Stock [Member] Public Offering [Member] | Jul. 15, 2011 Common Stock [Member] Public Offering [Member] | Mar. 30, 2011 Common Stock [Member] Public Offering [Member] | May 25, 2010 Common Stock [Member] Public Offering [Member] | May 25, 2010 Common Stock [Member] Public Offering [Member] | May 19, 2010 Common Stock [Member] Public Offering [Member] | Dec. 31, 2012 Common Stock [Member] 1999 Stock Option Plan [Member] | Dec. 31, 2012 Common Stock [Member] 2005 Stock Incentive Plan [Member] | Apr. 20, 2006 Common Stock [Member] 2005 Stock Incentive Plan [Member] | Apr. 19, 2006 Common Stock [Member] 2005 Stock Incentive Plan [Member]
Common Stock Options, Restricted Stock, Warrants And Changes In Capitalization [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of shares available for grant (shares) |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 883,000 |  | 3,000,000 | 1,904,606
Aggregate options granted (shares) |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 627,337 |  |  |
Number of options granted (shares) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 997,269 |  |
Issuance of common stock in public offering, shares |  |  |  |  |  |  |  | 11,750,000 | 4,600,000 | 3,450,000 | 2,760,000 |  |  | 1,481,481 |  |  |  |
Stock option, portion attributable to underwriters (shares) |  |  |  |  |  |  |  | 750,000 |  |  |  | 187,022 |  |  |  |  |  |
Stock option, portion available to underwriters (shares) |  |  |  |  |  |  |  | 1,650,000 |  |  |  |  |  |  |  |  |  |
Share price (usd per share) |  |  |  |  |  |  |  | $ 38 | $ 29 | $ 28.75 | $ 32 |  |  | $ 13.50 |  |  |  |
Proceeds from issuance of common stock, net of offering costs, and exercise of stock options | $ 427,900 | $ 427,091 | $ 307,154 | $ 21,879 |  |  |  | $ 427,900 | $ 128,000 | $ 94,700 | $ 84,300 |  | $ 21,600 |  |  |  |  |
Private placement offering units |  |  |  |  |  | 10,000 |  |  |  |  |  |  |  |  |  |  |  |
Number of shares called by each warrant (shares) |  |  |  |  |  | 250 |  |  |  |  |  |  |  |  |  |  |  |
Common stock, par value (usd per share) |  | $ 0.01 | $ 0.01 |  |  | $ 0.01 |  |  |  |  |  |  |  |  |  |  |  |
Preferred stock dividend rate |  | 12.00% | 12.00% |  |  | 12.00% |  |  |  |  |  |  |  |  |  |  |  |
Preferred stock divinded rate (for stock) |  |  |  |  |  | 15.00% |  |  |  |  |  |  |  |  |  |  |  |
Warrants outstanding |  |  |  |  |  | 2,322,962 |  |  |  |  |  |  |  |  |  |  |  |
Term of warrants |  |  |  |  |  | 10 years |  |  |  |  |  |  |  |  |  |  |  |
Exercise price of warrants issued (usd per share) |  |  |  |  |  |  | 1.19 |  |  |  |  |  |  |  |  |  |  |
Warrants expired |  |  |  |  | 8,875 |  |  |  |  |  |  |  |  |  |  |  |  |

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