EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Numerator:
Net earnings (loss)	$ (9.6)	$ 21.7	$ 1.3	$ 39.6
Denominator: (shares in thousands)
Denominator for basic earnings per share - weighted-average shares (in shares)	49,084,000	48,855,000	49,029,000	48,815,000
Potentially dilutive shares resulting from stock plans (in shares)	0	459,000	478,000	438,000
Denominator for diluted earnings per share - weighted-average shares (in shares)	49,084,000	49,314,000	49,507,000	49,253,000
Net earnings (loss) per share:
Basic (in dollars per share)	$ (0.20)	$ 0.44	$ 0.03	$ 0.81
Diluted (in dollars per share)	$ (0.20)	$ 0.44	$ 0.03	$ 0.80
Anti-dilutive equity awards not included in weighted-average common shares—diluted (in shares)	1,200,000		100,000