DEBT (Details 2) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
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	19.0		19.0		26.0
Unamortized bond discount	(2.2)		(2.2)		(2.8)
Long-term debt	1,516.8		1,516.8		1,523.2
Long-term debt - fair value	1,615.9		1,615.9
Interest expense	14.5	18.3	45.3	53.3
Interest income	(2.2)	(1.4)	(6.4)	(4.3)
Interest expense-net	12.3	16.9	38.9	49.0
Interest Costs Capitalized	1.5	0	3.7	0
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