FAIR VALUE MEASUREMENTS, INCLUDING DERIVATIVES (Tables)

9 Months Ended

Sep. 30, 2015

Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]

Fair value measurements, and the level within the fair value hierarchyin which the measurements fall, were as follows:

	As of September 30, 2015				As of December 31, 2014
Millions of dollars	Level 1		Level 2		Level 1		Level 2
Assets:
Available for sale securities	$	13	—		$	13	—
Interest rate contracts	—		$	6	—		—
Commodity contracts	—		—		1		—
Energy management contracts	—		15		—		$	20
Liabilities:
Interest rate contracts	—		202		—		257
Commodity contracts	1		6		1		11
Energy management contracts	2		15		5		18

Fair Value, by Balance Sheet Grouping [Table Text Block]

Financial instruments for which the carrying amount may not equal estimated fair value were as follows:

	September 30, 2015				December 31, 2014
Millions of dollars	Carrying Amount		Estimated Fair Value		Carrying Amount		Estimated Fair Value
Long-term debt	$	6,034.3	$	6,623.3	$	5,697.2	$	6,592.1

SCEG

Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]

Fair value Level 2 measurements were as follows:

Millions of dollars		September 30, 2015		December 31, 2014
Assets -	Interest rate contracts	$	6	—
Liabilities -	Interest rate contracts	178		$	233

Fair Value, by Balance Sheet Grouping [Table Text Block]

Financial instruments for which the carrying amount may not equal estimated fair value were as follows:

	September 30, 2015				December 31, 2014
Millions of dollars	Carrying Amount		Estimated Fair Value		Carrying Amount		Estimated Fair Value
Long-term debt	$	4,801.0	$	5,277.6	$	4,308.6	$	5,070.9