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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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Unrecognized cost of unvested share-based compensation awards.

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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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Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Number of options or other stock instruments for which the right to exercise has lapsed under the terms of the plan agreements.

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The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan.

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Gross number of share options (or share units) granted during the period.

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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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Number of options outstanding, including both vested and non-vested options.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options of the plan that expired.

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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options that were terminated.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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Number of share options (or share units) exercised during the current period.

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Stock Options (Details) (USD $)	3 Months Ended
Stock Options (Details) (USD $)	Mar. 31, 2015	Mar. 31, 2014	Apr. 05, 2012
Stock options under 2012 Plan
Stock option details
Shares available for future grants	204,000		800,000
Maximum exercisable period for options granted	10 years
Stock option activity
Options outstanding at the beginning of the period (in shares)	993,889
Plus: Options granted (in shares)	5,000
Less:
Options exercised (in shares)	3,100
Options expired (in shares)	28,325
Options forfeited (in shares)	7,971
Options outstanding at the end of the period (in shares)	959,493
Options fully vested and exercisable at the end of the period (in shares)	243,928
Stock options, weighted average exercise price
Options outstanding at the beginning, weighted average exercise price (in dollars per share)	$ 18.94
Plus: Options granted, weighted average exercise price (in dollars per share)	$ 24.15
Less:
Options exercised, weighted average exercise price (in dollars per share)	$ 16.85
Options expired, weighted average exercise price (in dollars per share)	$ 26.90
Options forfeited, weighted average exercise price (in dollars per share)	$ 17.57
Options outstanding at the end, weighted average exercise price (in dollars per share)	$ 18.75
Options fully vested and exercisable at the end, weighted average exercise price (in dollars per share)	$ 16.13
Stock options, weighted average remaining contractual term
Options outstanding at the end, weighted average remaining contractual term	6 years 7 months 2 days
Options fully vested and exercisable at the end, weighted average remaining contractual term	3 years 7 days
Stock options, aggregate intrinsic value
Options outstanding at the end, aggregate intrinsic value	$ 6,993,000
Options fully vested and exercisable at the end, aggregate intrinsic value	2,427,000
Stock-based compensation expense	292,000	161,000
Stock-based compensation cost, unrecognized, related to non-vested options	$ 3,759,000
Stock-based compensation cost, unrecognized, related to non-vested options, weighted-average period of recognition	2 years 2 months 12 days
Incentive stock options granted to 10% shareholders
Stock option details
Maximum exercisable period for options granted	5 years