SEGMENT OF BUSINESS INFORMATION (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Segment Reporting Information [Line Items]
Electric Domestic Regulated Revenue	$ 679	$ 626	$ 1,256	$ 1,217
Revenues	0	0	0	0
Net Income (Loss) Available to Common Stockholders, Basic	121	105	292	281
Operating Income	249	221	565	551
Regulated Operating Revenue, Gas	140	127	461	426
Regulated and Unregulated Operating Revenue	1,001	905	2,173	2,077
Segment Assets	19,056		19,056		$ 18,707
Electric Operations
Segment Reporting Information [Line Items]
Electric Domestic Regulated Revenue	679	625	1,256	1,217
Revenues	2	2	3	3
Operating Income	245	222	423	420
Segment Assets	12,377		12,377		11,929
Gas Distribution
Segment Reporting Information [Line Items]
Revenues	1	0	1	1
Operating Income	3	(1)	116	93
Regulated and Unregulated Operating Revenue	140	127	461	426
Segment Assets	3,032		3,032		2,892
Gas Marketing [Member]
Segment Reporting Information [Line Items]
Revenues	34	26	58	48
Net Income (Loss) Available to Common Stockholders, Basic	1	0	16	24
Regulated and Unregulated Operating Revenue	182	153	456	434
Segment Assets	195		195		230
All Other [member]
Segment Reporting Information [Line Items]
Revenues	102	104	196	202
Net Income (Loss) Available to Common Stockholders, Basic	(7)	(7)	(7)	(7)
Operating Income	0	0	0	0
Regulated and Unregulated Operating Revenue	0	0	0	0
Segment Assets	1,031		1,031		1,124
Adjustments/Eliminations
Segment Reporting Information [Line Items]
Revenues	(139)	(132)	(258)	(254)
Net Income (Loss) Available to Common Stockholders, Basic	127	112	283	264
Operating Income	1	0	26	38
Regulated and Unregulated Operating Revenue	0	0	0	0
Segment Assets	2,421		2,421		2,532
SCEG
Segment Reporting Information [Line Items]
Operating Income	246	222	468	458
Net Income (Loss) Attributable to Parent	123	110	231	223
Segment Assets	16,484		16,484		16,091
Regulated Operating Revenue	756	692	1,476	1,409
SCEG | Electric Operations
Segment Reporting Information [Line Items]
Electric Domestic Regulated Revenue	680	627	1,259	1,220
Operating Income	246	222	424	420
Segment Assets	12,377		12,377		11,929
SCEG | Gas Distribution
Segment Reporting Information [Line Items]
Operating Income	0	0	44	38
Regulated and Unregulated Operating Revenue	76	65	217	189
Segment Assets	848		848		825
SCEG | Adjustments/Eliminations
Segment Reporting Information [Line Items]
Operating Income	0	0	0	0
Regulated and Unregulated Operating Revenue	0	0	0	0
Net Income (Loss) Attributable to Parent	123	$ 110	231	$ 223
Segment Assets	$ 3,259		$ 3,259		$ 3,337