QUARTERLY FINANCIAL INFORMATION (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Regulated and Unregulated Operating Revenue	$ 1,057	$ 1,093	$ 905	$ 1,172	$ 956	$ 1,068	$ 967	$ 1,389	$ 4,227	$ 4,380	$ 4,951
Operating Income (Loss)	253	348	221	331	214	292	216	586	1,153	1,308	1,007
Income Available to Common Shareholders	$ 125	$ 189	$ 105	$ 176	$ 98	$ 149	$ 99	$ 400	$ 595	$ 746	$ 538
Earnings Per Share, Basic and Diluted	$ 0.87	$ 1.32	$ 0.74	$ 1.23	$ 0.69	$ 1.04	$ 0.69	$ 2.80	$ 4.16	$ 5.22	$ 3.79
SCE&G
Regulated Operating Revenue	$ 695	$ 882	$ 692	$ 717	$ 643	$ 806	$ 709	$ 772	$ 2,986	$ 2,930	$ 3,091
Operating Income (Loss)	196	359	222	236	172	307	218	237	1,013	934	830
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	93	204	113	116	76	167	111	126	526	480	458
Net Income (Loss) Attributable to Parent	$ 89	$ 201	$ 110	$ 113	$ 73	$ 164	$ 107	$ 122	$ 513	$ 466	$ 446