EMPLOYEE STOCK BENEFIT PLANS (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Stock-based compensation expense
Total pre-tax stock-based compensation expense	$ 5.9	$ 10.4	$ 23.8	$ 30.9
Net tax benefit related to stock-based compensation expense	(2.5)	(3.6)	(9.1)	(10.7)
Stock options
Stock-based compensation expense
Total pre-tax stock-based compensation expense	1.8	1.6	5.5	4.4
Performance share awards
Stock-based compensation expense
Total pre-tax stock-based compensation expense	2.0	6.0	11.8	18.2
Restricted stock units
Stock-based compensation expense
Total pre-tax stock-based compensation expense	$ 2.1	$ 2.8	$ 6.5	$ 8.3