STOCKHOLDERS' EQUITY AND SHARE-BASED COMPENSATION EXPENSE - Stock Options Plan Activity (Details) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($) $ / shares shares
Options, Outstanding [Roll Forward]
Outstanding at beginning of the period (in shares) | shares	4,195
Grants (in shares) | shares	504
Exercises (in shares) | shares	(1,138)
Forfeitures or expirations (in shares) | shares	(156)
Outstanding at end of the period (in shares) | shares	3,405
Exercisable (in shares) | shares	2,091
Vested and expected to vest (in shares) | shares	3,178
Weighted Average Exercise Price Per Share [Roll Forward]
Outstanding at beginning of the period (in dollars per share) | $ / shares	$ 6.23
Grants (in dollars per share) | $ / shares	11.00
Exercises (in dollars per share) | $ / shares	7.24
Forfeitures or expirations (in dollars per share) | $ / shares	9.36
Outstanding at end of the period (in dollars per share) | $ / shares	6.46
Exercisable (in dollars per share) | $ / shares	5.65
Vested and expected to vest (in dollars per share) | $ / shares	$ 6.31
Weighted-Average Remaining Contractual Terms [Abstract]
Outstanding at end of the period	3 years 7 months 10 days
Exercisable	2 years 6 months 29 days
Vested and expected to vest	3 years 5 months 19 days
Aggregate Intrinsic Value [Abstract]
Outstanding at end of the period | $	$ 13,662
Exercisable | $	9,995
Vested and expected to vest | $	$ 13,184