Represents the number of active plans under which future awards may be granted.

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The period of time, from the grant date until the time at which the share-based [option] award expires.

+ 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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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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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No definition available.

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- Definition

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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- 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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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
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- Definition

The aggregate cash inflow comprised of the amount received from (a) employees to acquire the entity's shares under incentive awards, including stock option exercises and restricted stock arrangements, and (b) the excess tax benefit arising from such transactions.

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No definition available.

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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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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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STOCK-BASED COMPENSATION (Details - Plan Information and P&L Impact) $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($) plan shares	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Unrecognized compensation cost
Number of active plans \| plan	2
Term of plan	10 years
Proceeds and Excess Tax Benefit from Share-based Compensation	$ 77,600	$ 12,900
Non-cash compensation expense related to equity awards
Non-cash stock-based compensation expense before income taxes	44,365	23,361	$ 9,647
Income tax benefit related to non-cash compensation	11,200	9,500	3,700
Cost of revenue
Non-cash compensation expense related to equity awards
Non-cash stock-based compensation expense before income taxes	378	175	129
Selling and marketing expense
Non-cash compensation expense related to equity awards
Non-cash stock-based compensation expense before income taxes	3,568	3,973	2,722
General and administrative expense
Non-cash compensation expense related to equity awards
Non-cash stock-based compensation expense before income taxes	34,325	16,874	4,699
Product development
Non-cash compensation expense related to equity awards
Non-cash stock-based compensation expense before income taxes	6,094	$ 2,339	$ 2,097
Employee Stock Option [Member]
Unrecognized compensation cost
Unrecognized compensation cost	$ 15,800
Weighted-average period for recognition of unrecognized compensation cost	2 years 3 months 20 days
Performance Shares [Member]
Unrecognized compensation cost
Unrecognized compensation cost	$ 10,300
RSUs
Unrecognized compensation cost
Unrecognized compensation cost	$ 30,500
Weighted-average period for recognition of unrecognized compensation cost	2 years
Restricted Stock
Unrecognized compensation cost
Weighted-average period for recognition of unrecognized compensation cost	1 year
Equity Award Plan [Member]
Unrecognized compensation cost
Number of shares authorized \| shares	5,350,000.00
Inducement Plan [Member]
Unrecognized compensation cost
Number of shares authorized \| shares	500,000.0