NET INCOME (LOSS) PER SHARE - Schedule of Computation of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Numerator:
Net income (loss)	$ 2,765	$ (5,128)
Denominator:
Weighted average common shares outstanding (in shares)	108,195	91,422
Employee stock-based awards	7,668	0
Weighted average common shares outstanding for diluted calculation	115,863	91,422
Net loss per share, basic (in USD per share)	$ 0.03	$ (0.06)
Net income (loss) per share, diluted (in usd per share)	$ 0.02	$ (0.06)