CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) shares in Millions, $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Common Stock, Shares, Outstanding	143.0	143.0
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	$ 135	$ 138
Public Utilities, Property, Plant and Equipment, Net	10,435	14,324
Allowance for Doubtful Accounts Receivable, Current	5	6
Write-down, Goodwill	230	230
Assets, Current	2,164	1,506
Regulated Entity, Other Assets, Noncurrent	$ 6,939	$ 2,402
SCEG
Common Stock, Shares, Outstanding	40.3	40.3
Public Utilities, Property, Plant and Equipment, Net	$ 8,508	$ 12,603
Allowance for Doubtful Accounts Receivable, Current	4	3
Assets, Current	1,917	1,020
Regulated Entity, Other Assets, Noncurrent	6,803	2,273
SCEG | Variable Interest Entity, Primary Beneficiary [Member]
Public Utilities, Property, Plant and Equipment, Net	740	756
Assets, Current	57	85
Regulated Entity, Other Assets, Noncurrent	$ 49	$ 52