RISK MANAGMENT ACTIVITIES (Details 4) (Utility segments)	Dec. 31, 2013 Btu	Dec. 31, 2012 Btu
Purchases | Natural gas contracts
Risk management activities
Notional volume of outstanding non-hedge derivative contracts (therms)	3,124,800,000	1,072,600,000
Purchases | Petroleum product contracts
Risk management activities
Notional volume of outstanding non-hedge derivative contracts (barrels)	102,811.0	62,811.0
Purchases | Coal contracts
Risk management activities
Notional volume of outstanding non-hedge derivative contracts (tons)	4,800,000	5,100,000
Sales | Natural gas contracts
Risk management activities
Notional volume of outstanding non-hedge derivative contracts (therms)	29,300,000	100,000
Sales | Petroleum product contracts
Risk management activities
Notional volume of outstanding non-hedge derivative contracts (barrels)	14,000.0	0.0
Sales | Coal contracts
Risk management activities
Notional volume of outstanding non-hedge derivative contracts (tons)	0	0
Other transactions | FTRs
Risk management activities
Notional volume of outstanding non-hedge derivative contracts (kwh)	3,633,100,000	4,057,200,000