AFFILIATED TRANSACTIONS -SCEG (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014	Sep. 30, 2014
Canadys Refined Coal [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Amounts of Transaction	$ 49.4	$ 69.9	$ 119.1	$ 108.9
Due to Affiliate, Current	23.7		23.7		$ 27.9
Due from Affiliate, Current	$ 23.6		$ 23.6		27.8
Equity Method Investment, Ownership Percentage	40.00%		40.00%
CGT [Member]
Related Party Transaction [Line Items]
Related Party Transaction Purchases from Related Party		8.8	$ 3.4	14.7
Due to Affiliate, Current					3.3
Due from Affiliate, Current					1.2	$ 0.0
Energy Marketing [Member]
Related Party Transaction [Line Items]
Due to Affiliate, Current	$ 10.2		10.2		12.6
Cost of Natural Gas Purchases	32.8	53.9	67.3	107.3
Canadys Refined Coal [Member]
Related Party Transaction [Line Items]
Related Party Transaction Purchases from Related Party	49.6	70.2	119.7	109.5
SCANA Services [Member]
Related Party Transaction [Line Items]
Due to Affiliate, Current	46.0		46.0		$ 47.3
Related Party Transaction, Expenses from Transactions with Related Party	$ 72.1	$ 70.2	$ 145.2	$ 146.4