| **Common Stock (Details) (USD $)**                                                                                                                              | 9 Months Ended |        | 0 Months Ended |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------|--------|----------------|
||
| **Class of Stock [Line Items]**                                                                                                                                 |           |   |           |  |   |
| Equity Issuance, Date                                                                                                                                           |           |   |           |  | May 21,         2012 |
| Stock Issued During Period, Shares, New Issues                                                                                                                  |           |   |           |  | 6,500,000 |
| Sale of Stock, Price Per Share                                                                                                                                  |           |   |           |  | $ 26.50 |
| Proceeds from Issuance of Common Stock                                                                                                                          | $ 164,496,000  | $ 0    |           |  | $ 164,500,000 |
| Common shares, par value $0.01 per share, 100,000,000 authorized, 30,269,648 and 23,634,958 issued as of September 30, 2012 and December 31, 2011, respectively | 303,000        |   | 236,000        | [1] | 65,000 |
| Additional paid-in capital                                                                                                                                      | $ 386,944,000  |   | $ 217,707,000  | [1] | $ 164,400,000 |
|                                                                                                                                                                 |
| [1]Derived from audited 2011 balance sheet.                                                                                                                     |

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| - Definition
Excess of issue price over par or stated value of the entity's capital stock and amounts received from other transactions involving the entity's stock or stockholders. Includes adjustments to additional paid in capital. Some examples of such adjustments include recording the issuance of debt with a beneficial conversion feature and certain tax consequences of equity instruments awarded to employees. Use this element for the aggregate amount of additional paid-in capital associated with common and preferred stock. For additional paid-in capital associated with only common stock, use the element additional paid in capital, common stock. For additional paid-in capital associated with only preferred stock, use the element additional paid in capital, preferred stock.
+ References
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|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Aggregate par or stated value of issued nonredeemable common stock (or common stock redeemable solely at the option of the issuer). This item includes treasury stock repurchased by the entity. Note: elements for number of nonredeemable common shares, par value and other disclosure concepts are in another section within stockholders' equity.
+ References
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| - Definition
Date of equity securities issuance, in CCYY-MM-DD format.
+ References
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| - Definition
The cash inflow from the additional capital contribution to the entity.
+ References
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| - Definition
Per share amount received by subsidiary or equity investee for each share of common stock issued or sold in the stock transaction.
+ References
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| - Definition
Number of new stock issued during the period.
+ References
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