v3.7.0.1

Common Stock - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions | Jul. 23, 2012 | Feb. 29, 2012
--- | --- | ---
IPO [Member] |  |
Class of Stock [Line Items] |  |
Common stock sold |  | 10,906,941
Sale of Stock, Price Per Share |  | $ 12
Proceeds from Issuance of Common Stock |  | $ 125.1
Sale of Stock, Consideration Received on Transaction |  | 112.8
Investment Banking, Advisory, Brokerage, and Underwriting Fees and Commissions |  | 8.8
Payments of Stock Issuance Costs |  | $ 3.5
Secondary Offering [Member] |  |
Class of Stock [Line Items] |  |
Common stock sold | 9,775,000 |
Sale of Stock, Price Per Share | $ 15.40 |
Proceeds from Issuance of Common Stock | $ 55.8 |
Sale of Stock, Consideration Received on Transaction | 51.9 |
Investment Banking, Advisory, Brokerage, and Underwriting Fees and Commissions | 2.7 |
Payments of Stock Issuance Costs | $ 1.2 |
Shares Offered By Company [Member] | IPO [Member] |  |
Class of Stock [Line Items] |  |
Common stock sold |  | 10,422,645
Shares Offered By Company [Member] | Secondary Offering [Member] |  |
Class of Stock [Line Items] |  |
Common stock sold | 3,625,000 |
Shares Offered By Selling Stockholders [Member] | IPO [Member] |  |
Class of Stock [Line Items] |  |
Common stock sold |  | 484,296
Shares Offered By Selling Stockholders [Member] | Secondary Offering [Member] |  |
Class of Stock [Line Items] |  |
Common stock sold | 6,150,000 |

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