v2.4.0.8

Organization and Basis of Presentation - Additional Information (Detail) (USD $) In Thousands, except Share data, unless otherwise specified | 1 Months Ended | 9 Months Ended | 12 Months Ended |
--- | --- | --- | --- | ---
Aug. 13, 2013 | Jul. 26, 2013 | Sep. 30, 2013 | Dec. 31, 2011 Subsidiary | Dec. 31, 2012
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items] |  |  |  |  |
Number of subsidiaries acquired |  |  |  | 3 |
Reverse stock split ratio |  | 1-for-1.75 |  |  |
Reverse stock split ratio |  | 0.57143 |  |  |
Aggregate proceeds from the IPO |  |  | $ 168,801 |  |
Shares of common stock | 79,705,130 |  |  |  |
Number of authorized shares of common stock | 200,000,000 |  | 200,000,000 | 155,000,000 | 160,000,000
Number of authorized shares of preferred stock | 25,000,000 |  |  |  |
IPO [Member] |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items] |  |  |  |  |
Shares of common stock | 11,499,998 |  |  |  |
Price per share of common stock | $ 16.00 |  |  |  |
Aggregate proceeds from the IPO | 168,300 |  |  |  |
Underwriting discounts and commissions | 12,900 |  |  |  |
Offering Expense paid | 2,800 |  |  |  |
Capitalized expenses | $ 2,300 |  |  |  |
Exercise of Overallotment Option by Underwriters [Member] |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items] |  |  |  |  |
Shares of common stock | 1,499,999 |  |  |  |

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