SHORT-TERM DEBT AND LINES OF CREDIT SHORT-TERM DEBT AND LINES OF CREDIT (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Short-term borrowings
Short-term borrowings outstanding	$ 388.0		$ 482.4
Commercial paper
Short-term borrowings
Short-term borrowings outstanding	188.0		482.4
Average interest rate (as a percent)	0.17%		0.40%
Average amount of short-term borrowings outstanding	423.0	299.2
Loan under term credit facility
Short-term borrowings
Short-term borrowings outstanding	$ 200.0		$ 0
Average interest rate (as a percent)	0.78%		0.00%