RISK MANAGEMENT ACTIVITIES (Details 2) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Assets
Gross Amount		$ 188.2
Gross Asset Amount Not Offset in the Balance Sheet, including Cash Collateral		148.4
Net Amount		39.8
Derivative assets not subject to master netting or similar arrangements		2.5
Risk Management Assets	243.9	190.7
Total risk management assets, Net Amount	98.2	42.3
Liabilities
Gross Amount	259.4	230.7
Gross Liability Not Offset in the Balance Sheet, including Cash Collateral	174.0	163.6
Net Amount	85.4	67.1
Derivative liabilities not subject to master netting or similar arrangement	3.0	9.6
Risk Management Liabilities	262.4	240.3
Total risk management liabilities, Net Amount	88.4	76.7
Nonregulated Segments
Assets
Gross Amount	236.8	182.5
Gross Asset Amount Not Offset in the Balance Sheet, including Cash Collateral	142.9	145.4
Net Amount	93.9	37.1
Liabilities
Gross Amount	251.2	215.4
Gross Liability Not Offset in the Balance Sheet, including Cash Collateral	170.8	159.8
Net Amount	80.4	55.6
Utility Segments
Assets
Gross Amount	7.1	5.7
Gross Asset Amount Not Offset in the Balance Sheet, including Cash Collateral	2.8	3.0
Net Amount	4.3	2.7
Liabilities
Gross Amount	8.2	15.3
Gross Liability Not Offset in the Balance Sheet, including Cash Collateral	3.2	3.8
Net Amount	$ 5.0	$ 11.5