RATE AND OTHER REGULATORY MATTERS ELECTRIC-BLRA (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Entity Information [Line Items]
Utilities Operating Expense, Impairments	$ 210.0		$ 1,118.0
Accumulated Carrying Costs Written Off			51.0
Regulatory Request to Lower Revenues			445.0
SCE&G
Entity Information [Line Items]
Utilities Operating Expense, Impairments			$ 1,118.0
Public Utilties increase (decrease) in retail electric rates				$ 64.4	$ 64.5
Public Utilities, Authorized Allowable Return on Common Equity, Percentage			10.50%	10.50%	11.00%
Public Utilities Percentage Change in Retail Electric Rates Approved under BLRA				2.70%	2.60%
Scenario, Forecast [Member] | SCE&G
Entity Information [Line Items]
Public Utilities, Authorized Allowable Return on Common Equity, Percentage		10.25%
Pension costs, electric [Member] | SCE&G
Entity Information [Line Items]
Regulatory Asset, Amortization Period			2044 years