FAIR VALUE MEASUREMENTS, INCLUDING DERIVATIVES (Details 2) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Carrying Amount
Financial instruments for which the carrying amount may not equal estimated fair value
Other Long-term Debt, Noncurrent	$ 5,121.0	$ 4,653.0
Estimated Fair Value
Financial instruments for which the carrying amount may not equal estimated fair value
Long-term debt	6,115.0	5,479.2
SCE&G | Carrying Amount
Financial instruments for which the carrying amount may not equal estimated fair value
Other Long-term Debt, Noncurrent	3,722.0	3,241.5
SCE&G | Estimated Fair Value
Financial instruments for which the carrying amount may not equal estimated fair value
Long-term debt	$ 4,543.1	$ 3,920.3