CHANGES IN COMMON STOCK (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	1 Months Ended	3 Months Ended		4 Months Ended	9 Months Ended
	May 31, 2020	Sep. 30, 2020	Sep. 30, 2019	Apr. 30, 2020	Sep. 30, 2020	Sep. 30, 2019
Equity, Class of Treasury Stock [Line Items]
Common stock repurchased		$ 50.0	$ 75.3		$ 163.0	$ 177.3
Stock repurchase program, remaining repurchase authorized amount		369.3			369.3
Common stock dividends declared		$ 17.0	$ 16.9		$ 50.4	$ 50.6
Dividends (in dollars per share)	$ 0.12			$ 0.11	$ 0.35
Common stock
Equity, Class of Treasury Stock [Line Items]
Stock repurchased and retired during period (in shares)		2,997	4,798		10,048	11,033
Common stock repurchased			$ 0.1		$ 0.1	$ 0.1