Share-Based Compensation - Unrecognized Share-Based Compensation Expense (Detail) $ in Thousands  | 
9 Months Ended | 
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| 
 Sep. 30, 2015  
USD ($) 
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| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
| Unrecognized Expense | $ 3,284 | 
| Average Expected Recognition Period | 1 year 9 months 18 days | 
| Stock option awards [Member] | |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
| Unrecognized Expense | $ 785 | 
| Average Expected Recognition Period | 1 year 3 months 18 days | 
| Restricted stock awards [Member] | |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
| Unrecognized Expense | $ 2,499 | 
| Average Expected Recognition Period | 1 year 10 months 24 days | 
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- Definition Unrecognized cost of unvested share-based compensation awards. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available. 
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