NET INCOME PER SHARE (Details) - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Jun. 15, 2015
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive potential common shares (in thousands of shares)	4,399	2,371	4,866
Stock options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive potential common shares (in thousands of shares)	3,670	1,901	4,748
Non-vested restricted stock units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive potential common shares (in thousands of shares)	729	470	118
Convertible Debt [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Long-term Debt, Gross	$ 125,000			$ 125,000