SHORT-TERM DEBT AND LINES OF CREDIT (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Short-term borrowings
Short-term borrowings outstanding	$ 347.2		$ 95.4
Commercial paper
Short-term borrowings
Short-term borrowings outstanding	147.2		95.4
Average discount rate (as a percent)	0.19%		0.24%
Average amount of short-term borrowings outstanding	70.8	164.8
Loan under term credit facility
Short-term borrowings
Short-term borrowings outstanding	$ 200.0
Average interest rate (as a percent)	0.80%