The conversion rate of RSU equity based awards to Common Stock.

No definition available.

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- Definition

Intrinsic value of equity-based compensation awards converted. Excludes stock and unit options.

+ References

No definition available.

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- Definition

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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- Definition

Aggregate cash paid by the entity during the period to settle equity instruments granted under equity-based payment arrangements.

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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

Amount of tax benefit from exercise of stock options granted under share-based compensation arrangement.

+ References

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- Definition

Amount of cash inflow from exercise of stock options granted under share-based compensation arrangement.

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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.

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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.

+ References

No definition available.

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- Definition

The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

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- Definition

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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- Definition

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

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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- Definition

Number of shares issued in lieu of cash for services contributed to the entity. Number of shares includes, but is not limited to, shares issued for services contributed by vendors and founders.

+ References

No definition available.

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Stock-based Compensation (Narrative) (Details)	3 Months Ended		12 Months Ended
Stock-based Compensation (Narrative) (Details)	Mar. 31, 2019 USD ($) shares	Mar. 31, 2018 USD ($) shares	Dec. 31, 2018	Dec. 31, 2017	Apr. 22, 2014 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense for share-based payments	$ 1,295,000	$ 1,128,000
Income tax benefits	390,000	340,000
Intrinsic value	203,000	205,000
Unrecognized compensation cost	$ 1,797,000
Weighted average period expected to be recognized	1 year 3 months 18 days
Proceeds from exercise of stock options	$ 203,000	96,000
Tax benefit from stock option exercised	$ 61,000	$ 62,000
Board Of Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued for services \| shares	1,462	557
RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total intrinsic value of RSUs converted	$ 2,107,000	$ 2,884,000
Unrecognized compensation cost	$ 1,796,000
Weighted average period expected to be recognized	1 year 3 months 18 days
Performance-Based RSUs [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Conversion rate of RSUs to common stock	1.50		1.50	1.25
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost	$ 1,000
Weighted average period expected to be recognized	1 year 2 months 12 days
Cash used to settle stock options	$ 0	$ 0
Equity Incentive Plan 2014 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized \| shares	2,250,000
Number of shares available for issuance \| shares	1,751,778
Equity Incentive Plan 2014 [Member] \| RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for issuance \| shares	298,633
Equity Incentive Plan 2014 [Member] \| RSUs [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized \| shares	787,500
Compensation Plan 2006 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized \| shares					0
Compensation Plan 2006 [Member] \| Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	5 years
Award expiration period	10 years