DERIVATIVE FINANCIAL INSTRUMENTS (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018 USD ($) MMBTU		Dec. 31, 2017 USD ($) MMBTU
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	66	[1]	62
Gas Distribution
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	6		6
Energy Marketing [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	60	[1]	55
Energy Related Derivative [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount | MMBTU	47	[1]	42
Energy Related Derivative [Member] | Energy Marketing [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	47		42
Commodity Contract [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	19		20
Commodity Contract [Member] | Gas Distribution
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	6		6
Commodity Contract [Member] | Energy Marketing [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	13		13
Basis Swap [Member] | Energy Related Derivative [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Energy Measure | MMBTU	5		3
Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Derivative, Notional Amount	$ 106.8		$ 111.2
Not Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Derivative, Notional Amount	35.0		735.0
SCE&G | Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Derivative, Notional Amount	36.4		36.4
SCE&G | Not Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Derivative, Notional Amount	$ 35.0		$ 735.0

[1] (a) Includes amounts related to basis swap contracts totaling 5.1 bcf in 2018 and 2.6 bcf in 2017.