FAIR VALUE MEASUREMENTS, INCLUDING DERIVATIVES (Details 2) - USD ($) $ in Millions |
Dec. 31, 2018 |
Dec. 31, 2017 |
|---|---|---|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
| Other Long-term Debt, Noncurrent | $ 6,753.9 | $ 6,632.9 |
| Long-term debt, Fair Value | 7,180.8 | 7,399.7 |
| SCE&G | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
| Other Long-term Debt, Noncurrent | 5,145.6 | 5,163.3 |
| Long-term debt, Fair Value | $ 5,469.7 | $ 5,790.3 |