NET INCOME PER SHARE (Details) - USD ($) shares in Thousands, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jun. 15, 2015
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted-average common shares outstanding - basic	43,060	42,913	42,560	42,046	41,860	41,792	41,587	41,404	42,649	41,662	41,020
Incremental Common Shares Attributable to Dilutive Effect of Conversion of Debt Securities									846	0	0
Anti-dilutive potential common shares (in thousands of shares)									3,207	3,837	5,353
Weighted-average common shares outstanding - diluted	43,737	43,674	42,560	42,046	42,430	42,226	41,587	41,404	43,495	41,662	41,020
Stock options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive potential common shares (in thousands of shares)									565	892	2,290
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)									2,642	2,945	3,063
Convertible Debt [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Long-term Debt, Gross												$ 125.0