FAIR VALUE (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Assets
Risk Management Asset	$ 2.4	$ 3.9
Liabilities
Risk Management Liability	3.1	9.7
Fair value measurements on a recurring basis
Transfers Between the Levels of the Fair Value Hierarchy
Fair Value Transfers, Amount	0	0
Fair value measurements on a recurring basis | Level 1
Assets
Risk Management Asset	0.7	0.2
Liabilities
Risk Management Liability	0.1	0.6
Fair value measurements on a recurring basis | Level 2
Assets
Risk Management Asset	0	0
Liabilities
Risk Management Liability	0	0
Fair value measurements on a recurring basis | Level 3
Assets
Risk Management Asset	1.7	3.7
Liabilities
Risk Management Liability	3.0	9.1
Fair value measurements on a recurring basis | Total
Assets
Risk Management Asset	2.4	3.9
Liabilities
Risk Management Liability	3.1	9.7
Fair value measurements on a recurring basis | Natural gas contracts | Level 1
Assets
Risk Management Asset	0.6	0.1
Liabilities
Risk Management Liability	0.1	0.6
Fair value measurements on a recurring basis | Natural gas contracts | Level 2
Assets
Risk Management Asset	0	0
Liabilities
Risk Management Liability	0	0
Fair value measurements on a recurring basis | Natural gas contracts | Level 3
Assets
Risk Management Asset	0	0
Liabilities
Risk Management Liability	0	0
Fair value measurements on a recurring basis | Natural gas contracts | Total
Assets
Risk Management Asset	0.6	0.1
Liabilities
Risk Management Liability	0.1	0.6
Fair value measurements on a recurring basis | FTRs | Level 1
Assets
Risk Management Asset	0	0
Liabilities
Risk Management Liability	0	0
Fair value measurements on a recurring basis | FTRs | Level 2
Assets
Risk Management Asset	0	0
Liabilities
Risk Management Liability	0	0
Fair value measurements on a recurring basis | FTRs | Level 3
Assets
Risk Management Asset	1.5	1.2
Liabilities
Risk Management Liability	0.3	0.1
Fair value measurements on a recurring basis | FTRs | Total
Assets
Risk Management Asset	1.5	1.2
Liabilities
Risk Management Liability	0.3	0.1
Fair value measurements on a recurring basis | Petroleum product contracts | Level 1
Assets
Risk Management Asset	0.1	0.1
Fair value measurements on a recurring basis | Petroleum product contracts | Level 2
Assets
Risk Management Asset	0	0
Fair value measurements on a recurring basis | Petroleum product contracts | Level 3
Assets
Risk Management Asset	0	0
Fair value measurements on a recurring basis | Petroleum product contracts | Total
Assets
Risk Management Asset	0.1	0.1
Fair value measurements on a recurring basis | Coal contract | Level 1
Assets
Risk Management Asset	0	0
Liabilities
Risk Management Liability	0	0
Fair value measurements on a recurring basis | Coal contract | Level 2
Assets
Risk Management Asset	0	0
Liabilities
Risk Management Liability	0	0
Fair value measurements on a recurring basis | Coal contract | Level 3
Assets
Risk Management Asset	0.2	2.5
Liabilities
Risk Management Liability	2.7	9.0
Fair value measurements on a recurring basis | Coal contract | Total
Assets
Risk Management Asset	0.2	2.5
Liabilities
Risk Management Liability	$ 2.7	$ 9.0