DERIVATIVE FINANCIAL INSTRUMENTS - Valuation Assumptions (Details) - Warrant - $ / shares	6 Months Ended	12 Months Ended
Jun. 30, 2016	Dec. 31, 2015
Derivative [Line Items]
Fair value of common stock (in dollars per share)	$ 17.81	$ 19.29
Dividend yield	0.00%	0.00%
Minimum
Derivative [Line Items]
Remaining life of the warrants (in years)	1 year 7 months 6 days	2 years 1 month 6 days
Risk-free interest rate	0.53%	1.11%
Expected volatility	65.00%	75.00%
Maximum
Derivative [Line Items]
Remaining life of the warrants (in years)	3 years 6 months	4 years
Risk-free interest rate	0.79%	1.59%
Expected volatility	85.00%	85.00%

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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

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- Definition

Expected dividends to be paid to holders of the underlying shares or financial instruments (expressed as a percentage of the share or instrument's price).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

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Measure of dispersion, in percentage terms (for instance, the standard deviation or variance), for a given stock price.

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Risk-free interest rate assumption used in valuing an instrument.

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Price of a single share of a number of saleable stocks of a company.

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