STOCK-BASED COMPENSATION (Tables)

6 Months Ended

Jun. 30, 2016

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

Stock option grants to employees generally have requisite service periods of four years, and stock option grants to non-employee directors generally have a requisite service period of one year. Both are subject to graded vesting. The Company records stock-based compensation expense associated with stock options on an accelerated basis over the various vesting periods within each grant and based on their fair value at the date of grant using the Black-Scholes-Merton option pricing model. The following weighted-average assumptions were used in the calculation of fair value for options grants for the three and six months ended June 30, 2016, respectively:

	Three Months Ended June 30, 2016		Six Months Ended June 30, 2016
Expected dividend yield	0	%	0	%
Risk-free interest rate	1.2	%	1.3	%
Expected volatility	38.2	%	38.3	%
Expected term (in years)	4.8		4.9

Schedule of Share-based Payment Award, Employee Stock Purchase Plan, Valuation Assumptions [Table Text Block]

The Company estimates the fair value of shares issued to employees under the ESPP using the Black-Scholes-Merton option-pricing model. The following weighted average assumptions were used in the calculation of fair value of shares under the ESPP at the grant date:

	June 30, 2016
Expected dividend yield	0	%
Risk-free interest rate	0.7	%
Expected volatility	32.4	%
Expected term (in years)	1.3