EMPLOYEE STOCK BENEFIT PLANS (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Stock-based compensation expense
Total pre-tax stock-based compensation expense	$ 9.1	$ 4.1	$ 26.9	$ 19.6
Net tax benefit related to stock-based compensation expense	(3.1)	(1.3)	(9.1)	(6.5)
Stock options
Stock-based compensation expense
Total pre-tax stock-based compensation expense	3.1	1.8	8.5	5.7
Performance share awards
Stock-based compensation expense
Total pre-tax stock-based compensation expense	1.7	(1.1)	6.3	4.4
Restricted stock units
Stock-based compensation expense
Total pre-tax stock-based compensation expense	$ 4.3	$ 3.4	$ 12.1	$ 9.5