DEBT (Details 2) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Long-Term Debt
Principal value of long-term debt obligations	$ 1,500.0		$ 1,500.0		$ 1,500.0
Unamortized basis adjustment for terminated interest rate swaps	30.6		30.6		35.3
Unamortized bond discount	(3.1)		(3.1)		(3.4)
Long-term debt	1,527.5		1,527.5		1,531.9
Long-term debt - fair value	1,696.0		1,696.0
Interest expense	18.8	14.5	35.0	28.9
Interest income	(1.2)	(2.3)	(2.9)	(3.6)
Interest expense-net	17.6	12.2	32.1	25.3
3.50% Notes due 2014
Long-Term Debt
Stated rate (as a percent)	3.50%		3.50%		3.50%
Principal value of long-term debt obligations	500.0		500.0		500.0
4.90% Notes due 2019
Long-Term Debt
Stated rate (as a percent)	4.90%		4.90%		4.90%
Principal value of long-term debt obligations	700.0		700.0		700.0
5.90% Notes due 2039
Long-Term Debt
Stated rate (as a percent)	5.90%		5.90%		5.90%
Principal value of long-term debt obligations	$ 300.0		$ 300.0		$ 300.0