INCOME TAXES (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended	12 Months Ended
	Mar. 31, 2019	Sep. 30, 2017	Dec. 31, 2016	Jun. 30, 2017
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued		$ 457
Unrecognized Tax Benefits that Would Impact Effective Tax Rate		17
Decrease in Unrecognized Tax Benefits is Reasonably Possible		$ 457
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent		3.00%	4.00%
SCEG
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued				$ 382
Unrecognized Tax Benefits that Would Impact Effective Tax Rate				17
Significant (Increase) Decrease in Unrecognized Tax Benefits is Reasonably Possible, Estimated Range of Change, Lower Bound				273
Decrease in Unrecognized Tax Benefits is Reasonably Possible				$ 53
SCANA [Member]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued		$ 402
Income Tax Authority [Domain]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent	2.50%