NET EARNINGS PER SHARE AND SHARE REPURCHASES Potential Shares Not Included in the Computation of Diluted Earnings (Loss) Per Share (Details) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share
Potential shares not included in the computation of diluted earnings (loss) per share	2,490	0	2,848	0
Restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share
Potential shares not included in the computation of diluted earnings (loss) per share	0	0	359	0
Performance share units
Antidilutive Securities Excluded from Computation of Earnings Per Share
Potential shares not included in the computation of diluted earnings (loss) per share	999	486	1,074	486