OTHER INCOME (EXPENSE), NET Other Income (Expense) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Contracts Revenue	$ 5	$ 0
Other income	129	17
Other Nonoperating Expense	(10)	(14)
Public Utilities, Allowance for Funds Used During Construction, Additions	4	9
Other Nonoperating Income (Expense)	128	12
SCEG
Contracts Revenue	1	0
Other income	126	8
Other Nonoperating Expense	(7)	(10)
Public Utilities, Allowance for Funds Used During Construction, Additions	3	9
Other Nonoperating Income (Expense)	$ 123	$ 7