EMPLOYEE STOCK BENEFIT PLANS (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Stock-based compensation expense
Total pre-tax stock-based compensation expense	$ 9.8	$ 8.3	$ 18.4	$ 17.9
Net tax benefit related to stock-based compensation expense	(3.3)	(2.9)	(6.2)	(6.7)
Stock options
Stock-based compensation expense
Total pre-tax stock-based compensation expense	1.6	1.9	3.3	3.7
Performance share awards
Stock-based compensation expense
Total pre-tax stock-based compensation expense	5.2	4.4	9.4	9.8
Restricted stock units
Stock-based compensation expense
Total pre-tax stock-based compensation expense	$ 3.0	$ 2.0	$ 5.7	$ 4.4