EMPLOYEE BENEFIT PLANS EMPLOYEE BENEFIT PLANS (Details 3) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Transfers of fair value amounts into or out of Levels 1, 2 or 3	no	no
Common collective trust [Member]
Defined Benefit Plan Disclosure [Line Items]
Alternative Investment, Fair Value Disclosure	$ 498	$ 453
Joint venture interests [Member]
Defined Benefit Plan Disclosure [Line Items]
Alternative Investment, Fair Value Disclosure	92	86
Alternative investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Alternative Investment, Fair Value Disclosure	850	794
Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	260	255
Fair Value, Inputs, Level 2 [Member] | Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	120	125
Fair Value, Inputs, Level 2 [Member] | Short-term Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	17	16
Fair Value, Inputs, Level 2 [Member] | Agency Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	15	18
Fair Value, Inputs, Level 2 [Member] | Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	91	82
Fair Value, Inputs, Level 2 [Member] | Municipal Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	$ 17	$ 14
SCE&G
Defined Benefit Plan Disclosure [Line Items]
Transfers of fair value amounts into or out of Levels 1, 2 or 3	no	no
SCE&G | Common collective trust [Member]
Defined Benefit Plan Disclosure [Line Items]
Alternative Investment, Fair Value Disclosure	$ 458	$ 418
SCE&G | Joint venture interests [Member]
Defined Benefit Plan Disclosure [Line Items]
Alternative Investment, Fair Value Disclosure	84	79
SCE&G | Alternative investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Alternative Investment, Fair Value Disclosure	781	733
SCE&G | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	239	236
SCE&G | Fair Value, Inputs, Level 2 [Member] | Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	110	115
SCE&G | Fair Value, Inputs, Level 2 [Member] | Short-term Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	16	15
SCE&G | Fair Value, Inputs, Level 2 [Member] | Agency Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	14	17
SCE&G | Fair Value, Inputs, Level 2 [Member] | Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	84	76
SCE&G | Fair Value, Inputs, Level 2 [Member] | Municipal Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	$ 15	$ 13