Shared-based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation			$ 1,192	$ 1,105
Proceeds from Stock Options Exercised			299	44
Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation			105
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation	$ 668	$ 575	1,200	1,100
Total income tax benefit recognized related to restricted stock awards	225	203	395	390
Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized	3,000		$ 3,000
Compensation cost recognition weighted average period			1 year 9 months 18 days
Share based compensation expense	137	129	$ 365	478
Award vesting period			5 years
Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation	9	165	$ 105	165
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized	700		$ 700
Compensation cost recognition weighted average period			2 years
Share-based compensation, shares authorized under stock option plans, exercise price range, lower range limit			$ 24.26
Share-based compensation arrangement by share-based payment award, options, grants in period, weighted average grant date fair value			7.91
Share-based compensation, shares authorized under stock option plans, exercise price range, upper range limit			$ 31.55
Proceeds from Stock Options Exercised	$ 300	$ 44	$ 300	$ 44
Share based compensation arrangement by share based payment award options expiration term			10 years

Expiration term for options outstanding during the reporting period.

No definition available.

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- Definition

Amount of increase in additional paid in capital (APIC) resulting from a tax benefit associated with share-based compensation plan other than an employee stock ownership plan (ESOP). Includes, but is not limited to, excess tax benefit.

+ References

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- Definition

The compensation expense recognized during the period pertaining to the deferred compensation arrangement.

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- Definition

Unrecognized cost of unvested share-based compensation awards.

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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.

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- Definition

The total recognized tax benefit related to compensation cost for equity-based payment arrangements recognized in income during the period.

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- Definition

The cash inflow associated with the amount received from holders exercising their stock options. This item inherently excludes any excess tax benefit, which the entity may have realized and reported separately.

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- Definition

The aggregate amount of noncash, equity-based employee remuneration. This may include the value of stock or unit options, amortization of restricted stock or units, and adjustment for officers' compensation. As noncash, this element is an add back when calculating net cash generated by operating activities using the indirect method.

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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.

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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.

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- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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- Definition

The floor of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

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The ceiling of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

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