FAIR VALUE MEASUREMENTS, INCLUDING DERIVATIVES (Details 2) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Long-term Debt, Noncurrent	$ 6,489.8	$ 5,997.6
Long-term debt, Fair Value	7,183.3	6,445.7
SCE&G
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Long-term Debt, Noncurrent	5,166.0	4,769.0
Long-term debt, Fair Value	$ 5,752.3	$ 5,129.1