EARNINGS (LOSS) PER SHARE (Antidilutive securities excluded from the computation of earnings (loss) per share) (Details) - shares	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock equivalents and outstanding stock options excluded from the calculation of diluted earnings (loss) per share (in thousands)	604,000	299,000	548,000	1,345,000	886,000	1,124,000	979,000	1,903,000	603,500	556,000	1,680,739
Unvested restricted stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock equivalents and outstanding stock options excluded from the calculation of diluted earnings (loss) per share (in thousands)									0	350,000	803,999
Unvested restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock equivalents and outstanding stock options excluded from the calculation of diluted earnings (loss) per share (in thousands)									480,000	0	119,940
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock equivalents and outstanding stock options excluded from the calculation of diluted earnings (loss) per share (in thousands)									123,500	206,000	756,800