XML 59 R49.htm IDEA: XBRL DOCUMENT v3.19.1
DERIVATIVE FINANCIAL INSTRUMENTS Derivative Financial Instruments (Credit Risk) (Details) - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2019
Mar. 31, 2018
Dec. 31, 2018
Derivative [Line Items]      
Additional Collateral, Aggregate Fair Value $ 0.0   $ 0.0
SCEG      
Derivative [Line Items]      
Collateral Already Posted, Aggregate Fair Value 14.0    
Derivative, Net Liability Position, Aggregate Fair Value 14.2    
Interest Rate Contract      
Derivative [Line Items]      
Derivative Liability, Fair Value, Gross Liability 14.0   $ 11.0
Not Designated as Hedging Instrument [Member] | Interest Rate Contract      
Derivative [Line Items]      
Derivative Instruments, Gain (Loss) Reclassified from Deferred Accounts into Income   $ 115.0  
Interest Expense [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contract      
Derivative [Line Items]      
Derivative Instruments, Gain (Loss) Reclassified from Deferred Accounts into Income $ 0.0    
Other Income [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contract      
Derivative [Line Items]      
Derivative Instruments, Gain (Loss) Reclassified from Deferred Accounts into Income   $ 115.0