STOCK-BASED COMPENSATION (Stock Options) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Underlying options (in shares)	1,554
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility (as a percent)	46.00%	46.00%	46.00%
Expected term (in years)	6 years 2 months 13 days	6 years 2 months 26 days	6 years 3 months
Risk free interest rate (as a percent)	2.01%	1.41%	1.13%
Dividend rate (as a percent)	0.00%	0.00%	0.00%
Unrecognized compensation cost, net of forfeitures	$ 41,669
Total unrecognized compensation cost related to non-vested share-based compensation awards granted, period for recognition (in years)	1 year 10 months 22 days
Weighted average remaining contractual term, exercisable (in years)	5 years 1 month 24 days
Weighted average remaining contractual term, outstanding (in years)	8 years 7 months
2012 Plan \| Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate grant-date fair value of stock options	$ 33,004
Share vesting term (in years)	4 years

Share-based Compensation Arrangement by Share-based Payment Award, Options, Granted, Fair Value

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- Definition

Underlying Options, Exercised

+ References

No definition available.

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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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

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- Definition

Unrecognized cost of unvested options awarded to employees as compensation.

+ References

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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

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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-Publisher FASB

-Name Accounting Standards Codification

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- Definition

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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-Publisher SEC

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-Section D

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- Definition

The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

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- Definition

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

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- Definition

Weighted average remaining contractual term for fully vested and expected to vest options that are 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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- Definition

Weighted average remaining contractual term for fully vested and expected to vest options outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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