EMPLOYEE STOCK BENEFIT PLANS (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Stock-based compensation expense
Total pre-tax stock-based compensation expense	$ 8.3	$ 11.5	$ 17.9	$ 20.5
Net tax benefit related to stock-based compensation expense	(2.9)	(4.0)	(6.7)	(7.1)
Stock options
Stock-based compensation expense
Total pre-tax stock-based compensation expense	1.9	1.4	3.7	2.8
Performance share awards
Stock-based compensation expense
Total pre-tax stock-based compensation expense	4.4	7.1	9.8	12.2
Restricted stock units
Stock-based compensation expense
Total pre-tax stock-based compensation expense	$ 2.0	$ 3.0	$ 4.4	$ 5.5