LONG-TERM AND SHORT-TERM DEBT (Details 2) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 2,000.0	$ 2,000.0
Commercial Paper	1,022.1	940.5
Letters of Credit Outstanding, Amount	3.3	3.3
Line of Credit Facility, Remaining Borrowing Capacity	974.6	1,056.2
five year credit [Domain]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	1,300.0	1,300.0
SCANA [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	400.0	400.0
Commercial Paper	$ 33.0	$ 64.4
Debt, Weighted Average Interest Rate	1.7773%	1.43%
Letters of Credit Outstanding, Amount	$ 3.0	$ 3.0
Line of Credit Facility, Remaining Borrowing Capacity	364.0	332.6
SCEG including Fuel Company [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	1,400.0	1,400.0
Commercial Paper	$ 944.8	$ 804.3
Debt, Weighted Average Interest Rate	1.49%	1.04%
Letters of Credit Outstanding, Amount	$ 0.3	$ 0.3
Line of Credit Facility, Remaining Borrowing Capacity	454.9	595.4
Fuel Company [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	500.0	500.0
Long-Term Line of Credit - SC Fuel Co only	500.0	500.0
SCEG
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	700.0	700.0
Long-term Line of Credit - SCE&G only	200.0	200.0
PSNC Energy [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	200.0	200.0
Commercial Paper	$ 44.3	$ 71.8
Debt, Weighted Average Interest Rate	1.49%	1.07%
Line of Credit Facility, Remaining Borrowing Capacity	$ 155.7	$ 128.2