INCOME TAXES (Details) - USD ($)	3 Months Ended	9 Months Ended		12 Months Ended
	Mar. 31, 2019	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued		$ 98,000,000
Unrecognized Tax Benefits that Would Impact Effective Tax Rate		98,000,000
Decrease in Unrecognized Tax Benefits is Reasonably Possible		11,000,000
Unrecognized Tax Benefits, Interest on Income Taxes Accrued		1.4
Deferred Tax Liabilities, Deferred Expense, Reserves and Accruals		$ 6,800,000
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent	2.50%	3.00%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		21.00%	35.00%	35.00%
SCEG
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued		$ 98,000,000
Unrecognized Tax Benefits that Would Impact Effective Tax Rate		98,000,000
Significant (Increase) Decrease in Unrecognized Tax Benefits is Reasonably Possible, Estimated Range of Change, Lower Bound		0
Decrease in Unrecognized Tax Benefits is Reasonably Possible		11,000,000
SCANA [Member]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued		$ 19,000,000