| Stock-Based Compensation Plans - 2013 Omnibus Equity Incentive Plan - Additional Information (Detail) - USD ($) | 1 Months Ended | 6 Months Ended | 
|---|---|---|
| Nov. 30, 2013 | Jun. 30, 2016 | |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||
| Number of common stock shares withheld to pay employee statutory withholding taxes | 40,408 | |
| Windfall tax benefits net from stock-based award activity included in additional paid-in capital | $ 171,000 | |
| Restricted Stock Awards [Member] | Non-Employee Directors [Member] | ||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||
| Vesting period | 3 years | 3 years | 
| Restricted Stock Units (RSUs) [Member] | ||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||
| Vesting period | 5 years | |
| Deferred stock units [Member] | ||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||
| Fully vested deferred stock units remaining outstanding | 1,365,445 | 
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- Definition Fully vested deferred stock units remaining outstanding. No definition available. 
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- Definition Amount of increase (decrease) in additional paid in capital (APIC) resulting from a tax benefit (deficiency) associated with an share-based compensation plan other than an employee stock ownership plan (ESOP). No definition available. 
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- Definition Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, 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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- Definition For net-share settlement of share-based awards when the employer settles employees' income tax withholding obligations, this element represents the number of shares the employees use to repay the employer. No definition available. 
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