NET INCOME (LOSS) PER SHARE (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Basic net income (loss) per share
Net income (loss)	$ (14,301)	$ 33,824
Denominator (in shares)	64,239	63,503
Basic net income (loss) per share (in dollars per share)	$ (0.22)	$ 0.53
Add: Interest Expense on convertible debt, net of tax	$ 0	$ 5,187
Add effect of diluted securities:
Stock options and equivalents and convertible debt (in shares)	0	18,374
Denominator for diluted (loss) income per share (in shares)	64,239	81,877
Diluted net income (loss) per share (in dollars per share)	$ (0.22)	$ 0.48
Potentially dilutive common shares:
Total potentially dilutive common shares (in shares)	24,034	4,248
Convertible debt
Potentially dilutive common shares:
Total potentially dilutive common shares (in shares)	17,931	0
Stock options and equivalents
Potentially dilutive common shares:
Total potentially dilutive common shares (in shares)	6,103	4,248