EMPLOYEE STOCK BENEFIT PLANS (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Stock-based compensation expense
Total pre-tax stock-based compensation expense	$ 10.0	$ 6.5	$ 17.8	$ 15.5
Net tax benefit related to stock-based compensation expense	(3.3)	(2.1)	(6.0)	(5.2)
Stock options
Stock-based compensation expense
Total pre-tax stock-based compensation expense	3.3	2.0	5.4	3.9
Performance share awards
Stock-based compensation expense
Total pre-tax stock-based compensation expense	2.3	1.1	4.6	5.5
Restricted stock units
Stock-based compensation expense
Total pre-tax stock-based compensation expense	$ 4.4	$ 3.4	$ 7.8	$ 6.1