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Stock Incentive Plan - Stock Options Activity (Details) (USD $)
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6 Months Ended |
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Jun. 30, 2012
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| Number of Options [Roll Forward] | |
| Outstanding at December 31, 2011 | 5,424,612 |
| Granted | 576,645 |
| Exercised | (755,463) |
| Forfeited | (2,850) |
| Outstanding at June 30, 2012 | 5,242,944 |
| Options exercisable at June 30, 2012 | 3,559,121 |
| Expected to vest at June 30, 2012 | 1,621,103 |
| Options exercisable at December 31, 2011 | 3,896,512 |
| Weighted Average Exercise Price [Roll Forward] | |
| Outstanding at December 31, 2011 (in usd per share) | $ 5.151 |
| Granted (in usd per share) | $ 11.816 |
| Exercised (in usd per share) | $ 2.382 |
| Forfeited (in usd per share) | $ 4.220 |
| Outstanding at June 30, 2012 (in usd per share) | $ 6.283 |
| Options exercisable at June 30, 2012 (in usd per share) | $ 4.353 |
| Expected to vest at June 30, 2012 (in usd per share) | $ 10.512 |
| Options exercisable at December 31, 2011 (in usd per share) | $ 3.773 |
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- Definition
The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Gross number of share options (or share units) granted during the period. No definition available.
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- Definition
The number of shares reserved for issuance under stock option agreements awarded under the plan that validly exist and are outstanding as of the balance sheet date, including vested options. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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- Definition
Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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- Definition
The number of exercisable share options (fully vested and expected to vest) that may be converted as of the balance sheet date. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
As of the balance sheet date, the weighted-average exercise price (at which grantees can acquire the shares reserved for issuance) for exercisable stock options that are fully vested or expected to vest. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Weighted average price at which option holders acquired shares when converting their stock options into shares. No definition available.
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- Definition
Weighted average price at which grantees could have acquired the underlying shares with respect to stock options that were terminated. No definition available.
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- Definition
Weighted average price at which grantees can acquire the shares reserved for issuance on stock options awarded. No definition available.
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- Definition
Number of share options (or share units) exercised during the current period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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