SHAREHOLDERS’ EQUITY AND SHARE-BASED COMPENSATION (Tables)

6 Months Ended

Jun. 30, 2015

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

Schedule of assumptions used to determine the fair value of options as of the grant date

The fair value of the service-based options was determined using the Black-Scholes option pricing model and the fair value of the market-based options was determined using a lattice (binomial) model. The following assumptions were used to determine the fair value as of the grant date:

	Six months ended   June 30, 2015		Six months ended   June 30, 2014
	Black-Scholes	Binomial	Black-Scholes
Risk-free interest rate (%)	1.50 - 1.78	0.02 - 2.26	1.80
Expected stock price volatility (%)	55.06 - 57.60	55.06 - 57.60	37.57
Expected dividend yield	—	—	—
Expected option life (in years)	6.00 - 6.25	—	6.25
Contractual life (in years)	—	13.00 - 14.00	—
Fair value	$10.01 - $16.05	$9.91 - $16.13	$41.79

Summary of the weighted average fair value of stock options granted, the total intrinsic value of stock options exercised and the fair value of options vested

The following table summarizes the weighted average grant date fair value of stock options granted, the total intrinsic value of stock options exercised and the grant date fair value of stock options that vested during the period presented:

	Six months ended June 30,
(in thousands, except per share amounts)	2015		2014
Weighted average grant date fair value of options granted per share	$	12.49	$	41.79
Intrinsic value of options exercised	176		4,124
Grant date fair value of options that vested during the period	530		950

Summary of the activity of the entity's stock options

The following table summarizes the activity related to our stock options:

	Number of options		Weighted average exercise price		Weighted average contractual term (in years)	Aggregate intrinsic value (in thousands)
Outstanding at December 31, 2014	2,601,892		$	21.21	4.44	$	47,805
Granted	710,410		23.17
Exercised	(21,984	)	9.19
Forfeited	(30,031	)	64.66
Outstanding at June 30, 2015	3,260,287		21.45		5.22	46,119
Exercisable at June 30, 2015	2,281,382		14.34		3.49	40,448

Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity [Table Text Block]

The restricted shares are service-based awards that vest over one to four years with either annual cliff-vesting, vesting of all of the restricted shares at the end of the vesting period or vesting beginning after two years of service. Restricted shares are granted at fair value on the date of grant. The Company granted 0.2 million restricted shares (at a weighted average price of $19.06 per share) during the six months ended June 30, 2015 (no comparative amount for the six months ended June 30, 2014). A total of 0.3 million service-based restricted shares were outstanding at June 30, 2015.

The following table summarizes the activity related to our restricted shares:

	Number of restricted shares
Outstanding at December 31, 2014	26,224
Granted	243,438
Issued	(2,836	)
Outstanding at June 30, 2015	266,826