RISK MANAGEMENT ACTIVITIES (Details 4)	Dec. 31, 2013 Btu	Dec. 31, 2012 Btu
Purchases | Natural gas contracts
Risk management activities
Notional volume of outstanding derivative contracts (therms)	2,242,500,000	86,100,000
Purchases | Petroleum product contracts
Risk management activities
Notional volume of outstanding derivative contracts (barrels)	73,002.0	33,002.0
Purchases | Coal contract
Risk management activities
Notional volume of outstanding derivative contracts (tons)	4,800,000	5,100,000
Sales | Natural gas contracts
Risk management activities
Notional volume of outstanding derivative contracts (therms)	7,000,000
Sales | Petroleum product contracts
Risk management activities
Notional volume of outstanding derivative contracts (barrels)	14,000.0
Sales | Coal contract
Risk management activities
Notional volume of outstanding derivative contracts (tons)	0
Other Transactions | FTRs
Risk management activities
Notional volume of outstanding derivative contracts (kwh)	3,427,000,000	3,838,200,000