MISCELLANEOUS INCOME (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Other Income and Expenses [Abstract]
Equity portion of AFUDC	$ 2.2	$ 2.9	$ 8.5	$ 6.6
Earnings from equity method investments	2.9	2.8	8.5	8.6
Key executive life insurance for retired employees	0.1	0.1	1.5	1.0
Other	0.4	0.2	1.0	0.7
Total miscellaneous income	$ 5.6	$ 6.0	$ 19.5	$ 16.9