Share-Based Compensation - Additional Information (Detail) (USD $)	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Recognized share-based compensation awards	$ 500,000	$ 400,000
Weighted-average fair value of stock options granted	$ 7.15	$ 7.77
Expected Volatility Rate	54.00%	57.00%
Expected Term Period	6 years 6 months	6 years 4 months 24 days
Risk-Free Interest Rate	2.00%	2.30%
Expected dividend rate	1.60%	1.30%
Cash received from employees and directors stock option exercised	2,000us-gaap_ProceedsFromStockPlans	500,000us-gaap_ProceedsFromStockPlans
Intrinsic value of option exercised	$ 15,000	$ 1,000,000

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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-Publisher FASB

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The cash inflow associated with the amount received from the stock plan during the period.

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-Glossary Financing Activities

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The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.

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Expected term of share-based compensation awards, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The risk-free interest rate assumption that is used in valuing an option on its own shares.

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Weighted average expected volatility rate of share-based compensation awards.

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Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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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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