CONSOLIDATED STATEMENTS OF COMMON EQUITY - USD ($) shares in Millions, $ in Millions	Total	AOCI Attributable to Parent [Member]	SCE&G	SCEG excluding VIEs [Member]	SCEG and GENCO [Member]	Subsidiaries [Member] SCE&G
Common Stock, Value, Outstanding				$ 2,760
Stockholders' Equity Attributable to Noncontrolling Interest					$ 129
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest			$ 5,151
Stockholders' Equity Attributable to Parent at Dec. 31, 2015	$ 5,443
Shares, Outstanding at Dec. 31, 2015	143			40
Stockholders' Equity before Treasury Stock at Dec. 31, 2015	$ 2,402
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax at Dec. 31, 2015	(53)
Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax at Dec. 31, 2015	(12)
Retained Earnings, Unappropriated at Dec. 31, 2015	3,118			$ 2,265
Treasury Stock, Value at Dec. 31, 2015	(12)
Accumulated Other Comprehensive Income (Loss) at Dec. 31, 2015	(65)			(3)
Dividends, Common Stock	(329)
Other comprehensive income (loss), unrealized holding gain (loss) net of reclassification to AOCI arising during period, net of tax	17
Net Income (Loss) Attributable to Noncontrolling Interest			13		13
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest			526
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax, Portion Attributable to Parent			0	0
Contributions from parent			100		0
Dividends			(305)	(297)
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders					(8)
Other Comprehensive Income (Loss), Net of Tax	16		0
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	4
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Remeasurement and Curtailment Adjustement, Net of Tax	(1)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax	13
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Reclassified During Period, Net of Tax	0		0
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	611		526	513
Proceeds from Contribution from Parent, net of return of Proceeds			100	100
Income Available to Common Shareholders	$ 595			$ 513
Dividends Declared Per Share of Common Stock (in dollars per share)	$ 2.30
Shares, Outstanding at Dec. 31, 2016	143			40
Stockholders' Equity before Treasury Stock at Dec. 31, 2016	$ 2,402
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax at Dec. 31, 2016	(36)
Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax at Dec. 31, 2016	(13)
Retained Earnings, Unappropriated at Dec. 31, 2016	3,384			$ 2,481
Treasury Stock, Value at Dec. 31, 2016	(12)
Accumulated Other Comprehensive Income (Loss) at Dec. 31, 2016	(49)			(3)
Stockholders' Equity Attributable to Parent at Dec. 31, 2016	5,725
Common Stock, Value, Outstanding				2,860
Stockholders' Equity Attributable to Noncontrolling Interest					134
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest			5,472
AOCI before Tax, Attributable to Parent	(13)	$ 3
Dividends, Common Stock	(350)
Other comprehensive income (loss), unrealized holding gain (loss) net of reclassification to AOCI arising during period, net of tax	(1)
Net Income (Loss) Attributable to Noncontrolling Interest			13		13
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest			(172)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax, Portion Attributable to Parent			1	(1)
Contributions from parent			3		3
Dividends			(322)	(314)
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders					(8)
Other Comprehensive Income (Loss), Net of Tax	(1)		(1)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	(7)
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Remeasurement and Curtailment Adjustement, Net of Tax	0
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax	6
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Reclassified During Period, Net of Tax	0		0
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	(120)		(173)	(186)
Proceeds from Contribution from Parent, net of return of Proceeds			100	0
Income Available to Common Shareholders	$ (119)			$ (185)
Dividends Declared Per Share of Common Stock (in dollars per share)	$ 2.45
Shares, Outstanding at Dec. 31, 2017	143			40
Stockholders' Equity before Treasury Stock at Dec. 31, 2017	$ 2,402
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax at Dec. 31, 2017	(37)
Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax at Dec. 31, 2017	(13)
Retained Earnings, Unappropriated at Dec. 31, 2017	2,915		1,982	$ 1,982
Treasury Stock, Value at Dec. 31, 2017	(12)
Accumulated Other Comprehensive Income (Loss) at Dec. 31, 2017	(50)			(4)
Stockholders' Equity Attributable to Parent at Dec. 31, 2017	5,255		4,838
Common Stock, Value, Outstanding	2,390		2,860	2,860
Stockholders' Equity Attributable to Noncontrolling Interest			142		142
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest			4,980
AOCI before Tax, Attributable to Parent	(6)	(7)
Dividends, Common Stock	(140)
Other comprehensive income (loss), unrealized holding gain (loss) net of reclassification to AOCI arising during period, net of tax	14
Net Income (Loss) Attributable to Noncontrolling Interest			25		25
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest			(589)			$ (589)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax, Portion Attributable to Parent			(1)	1
Contributions from parent			24		24
Dividends			(101)	(89)
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders					(12)
Other Comprehensive Income (Loss), Net of Tax	16		1
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	(2)
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Remeasurement and Curtailment Adjustement, Net of Tax	2
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax	16
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Reclassified During Period, Net of Tax	2		0
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	(512)		(588)	(613)
treasury stock issued	(1)
Proceeds from Contribution from Parent, net of return of Proceeds	24			0
Income Available to Common Shareholders	$ (528)			$ (614)
Dividends Declared Per Share of Common Stock (in dollars per share)	$ 0.98
Shares, Outstanding at Dec. 31, 2018	143			40
Stockholders' Equity before Treasury Stock at Dec. 31, 2018	$ 2,402
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax at Dec. 31, 2018	(23)
Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax at Dec. 31, 2018	(11)
Retained Earnings, Unappropriated at Dec. 31, 2018	2,247		1,279	$ 1,279
Treasury Stock, Value at Dec. 31, 2018	(13)
Accumulated Other Comprehensive Income (Loss) at Dec. 31, 2018	(34)			(3)
Stockholders' Equity Attributable to Parent at Dec. 31, 2018	4,602		4,136
Common Stock, Value, Outstanding	2,389		2,860	$ 2,860
Stockholders' Equity Attributable to Noncontrolling Interest			179		$ 179
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest			$ 4,315
AOCI before Tax, Attributable to Parent	$ (16)	$ 0