OTHER INCOME (EXPENSE), NET Other Income (Expense) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenue from Contract with Customer, Including Assessed Tax	$ 4		$ 14
Other income	8	$ 28	144	$ 61
Other Nonoperating Expense	(14)	(9)	(34)	(33)
Public Utilities, Allowance for Funds Used During Construction, Additions	5	0	12	17
Other Nonoperating Income (Expense)	3	19	136	45
SCEG
Revenue from Contract with Customer, Including Assessed Tax	1		4	0
Other income	5	21	135	36
Other Nonoperating Expense	(10)	(7)	(22)	(23)
Public Utilities, Allowance for Funds Used During Construction, Additions	3	(3)	7	13
Other Nonoperating Income (Expense)	$ (1)	$ 11	124	$ 26
Other Income [Member] | Interest Rate Contract | Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) Reclassified from Deferred Accounts into Income			$ 115