EARNINGS PER-SHARE (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Net Income
Net Income, Basic	$ 41.6	$ 34.1	$ 88.4	$ 65.1
Net Income, Diluted	$ 41.6	$ 34.1	$ 88.4	$ 65.1
Weighted Average Common Shares
Basic (in shares)	42.7	42.9	42.7	43.0
Effect of Dilutive Securities (in shares)	0.4	0.3	0.3	0.3
Diluted (in shares)	43.1	43.2	43.0	43.3
Per Common Share Amount
Net income, Basic (in dollars per share)	$ 0.97	$ 0.79	$ 2.07	$ 1.51
Effect of Dilutive Securities (in dollars per shares)			(0.01)	(0.01)
Net income, Diluted (in dollars per share)	$ 0.97	$ 0.79	$ 2.06	$ 1.50