Investments in Debt and Equity Securities (Tables)

12 Months Ended

Dec. 31, 2014

Schedule of Available-for-sale Securities [Line Items]

Available-For-Sale Investments

The following table presents the estimated fair value of investments in available-for-sale securities.

	December 31, 2014						December 31, 2013
(in millions)	Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Estimated Fair Value		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Estimated Fair Value
NDTF
Cash and cash equivalents	$	—	$	—	$	136	$	—	$	—	$	110
Equity securities	1,926		29		3,650		1,813		10		3,579
Corporate debt securities	14		2		454		8		6		400
Municipal bonds	5		—		184		2		6		160
U.S. government bonds	19		2		978		7		12		730
Other debt securities	1		2		147		22		2		154
Total NDTF	1,965		35		5,549		1,852		36		5,133
Other Investments
Cash and cash equivalents	—		—		15		—		—		21
Equity securities	34		—		96		29		—		91
Corporate debt securities	1		1		58		1		1		99
Municipal bonds	3		1		76		2		2		79
U.S. government bonds	—		—		27		—		—		17
Other debt securities	1		1		80		—		8		111
Total Other Investments(a)	39		3		352		32		11		418
Total Investments	$	2,004	$	38	$	5,901	$	1,884	$	47	$	5,551

(a) These amounts are recorded in Other within Investments and Other Assets on the Consolidated Balance Sheets.

Schedule of Maturity Dates for Debt Securities

The table below summarizes the maturity date for debt securities.

(in millions)	December 31, 2014
Due in one year or less	178
Due after one through five years	571
Due after five through 10 years	464
Due after 10 years	791
Total	2,004

Schedule of Realized Gain (Loss)

Realized gains and losses, which were determined on a specific identification basis, from sales of available-for-sale securities were as follows.

	Years Ended December 31,
(in millions)	2014		2013		2012
Realized gains	$	271	$	209	$	117
Realized losses	105		65		19

Duke Energy Carolinas [Member]

Schedule of Available-for-sale Securities [Line Items]

Available-For-Sale Investments

The following table presents the estimated fair value of investments in available-for-sale securities.

	December 31, 2014						December 31, 2013
(in millions)	Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Estimated Fair Value		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Estimated Fair Value
NDTF
Cash and cash equivalents	$	—	$	—	$	51	$	—	$	—	$	42
Equity securities	1,102		17		2,162		974		6		1,964
Corporate debt securities	8		2		316		5		5		274
Municipal bonds	1		—		62		—		2		54
U.S. government bonds	7		1		308		3		7		354
Other debt securities	1		2		133		22		2		146
Total NDTF	1,119		22		3,032		1,004		22		2,834
Other Investments
Other debt securities	—		1		3		—		1		3
Total Other Investments(a)	—		1		3		—		1		3
Total Investments	$	1,119	$	23	$	3,035	$	1,004	$	23	$	2,837

(a) These amounts are recorded in Other within Investments and Other Assets on the Consolidated Balance Sheets.

Schedule of Maturity Dates for Debt Securities

The table below summarizes the maturity date for debt securities.

(in millions)	December 31, 2014
Due in one year or less	$	1
Due after one through five years	155
Due after five through 10 years	257
Due after 10 years	409
Total	$	822

Schedule of Realized Gain (Loss)

Realized gains and losses, which were determined on a specific identification basis, from sales of available-for-sale securities were as follows.

	Years Ended December 31,
(in millions)	2014		2013		2012
Realized gains	$	109	$	115	$	89
Realized losses	93		12		6

Progress Energy [Member]

Schedule of Available-for-sale Securities [Line Items]

Available-For-Sale Investments

The following table presents the estimated fair value of investments in available-for-sale securities.

	December 31, 2014						December 31, 2013
(in millions)	Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Estimated Fair Value		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Estimated Fair Value
NDTF
Cash and cash equivalents	$	—	$	—	$	85	$	—	$	—	$	68
Equity securities	824		12		1,488		839		4		1,615
Corporate debt securities	6		—		138		3		1		126
Municipal bonds	4		—		122		2		4		106
U.S. government bonds	12		1		670		4		5		376
Other debt securities	—		—		14		—		—		8
Total NDTF	846		13		2,517		848		14		2,299
Other Investments
Cash and cash equivalents	—		—		15		—		—		20
Municipal bonds	3		—		43		1		—		39
Total Other Investments(a)	3		—		58		1		—		59
Total Investments	$	849	$	13	$	2,575	$	849	$	14	$	2,358

(a) These amounts are recorded in Other within Investments and Other Assets on the Consolidated Balance Sheets.

Schedule of Maturity Dates for Debt Securities

The table below summarizes the maturity date for debt securities.

(in millions)	December 31, 2014
Due in one year or less	$	161
Due after one through five years	350
Due after five through 10 years	157
Due after 10 years	319
Total	$	987

Schedule of Realized Gain (Loss)

Realized gains and losses, which were determined on a specific identification basis, from sales of available-for-sale securities were as follows.

	Years Ended December 31,
(in millions)	2014		2013		2012
Realized gains	$	157	$	90	$	34
Realized losses	11		46		18

Duke Energy Progress [Member]

Schedule of Available-for-sale Securities [Line Items]

Available-For-Sale Investments

The following table presents the estimated fair value of investments in available-for-sale securities.

	December 31, 2014						December 31, 2013
(in millions)	Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Estimated Fair Value		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Estimated Fair Value
NDTF
Cash and cash equivalents	$	—	$	—	$	50	$	—	$	—	$	48
Equity securities	612		10		1,171		535		3		1,069
Corporate debt securities	5		—		97		3		1		80
Municipal bonds	4		—		120		2		4		104
U.S. government bonds	9		1		265		4		3		232
Other debt securities	—		—		8		—		—		5
Total NDTF	630		11		1,711		544		11		1,538
Other Investments
Cash and cash equivalents	—		—		—		—		—		2
Total Other Investments(a)	—		—		—		—		—		2
Total Investments	$	630	$	11	$	1,711	$	544	$	11	$	1,540

(a) These amounts are recorded in Other within Investments and Other Assets on the Consolidated Balance Sheets.

Schedule of Maturity Dates for Debt Securities

The table below summarizes the maturity date for debt securities.

(in millions)	December 31, 2014
Due in one year or less	$	14
Due after one through five years	140
Due after five through 10 years	109
Due after 10 years	227
Total	$	490

Schedule of Realized Gain (Loss)

Realized gains and losses, which were determined on a specific identification basis, from sales of available-for-sale securities were as follows.

	Years Ended December 31,
(in millions)	2014		2013		2012
Realized gains	$	19	$	58	$	21
Realized losses	5		26		8

Duke Energy Florida [Member]

Schedule of Available-for-sale Securities [Line Items]

Available-For-Sale Investments

The following table presents the estimated fair value of investments in available-for-sale securities.

	December 31, 2014						December 31, 2013
(in millions)	Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Estimated Fair Value		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Estimated Fair Value
NDTF
Cash and cash equivalents	$	—	$	—	$	35	$	—	$	—	$	20
Equity securities	212		2		317		304		1		546
Corporate debt securities	1		—		41		—		—		46
Municipal bonds	—		—		2		—		—		2
U.S. government bonds	3		—		405		—		2		144
Other debt securities	—		—		6		—		—		3
Total NDTF	216		2		806		304		3		761
Other Investments
Cash and cash equivalents	—		—		1		—		—		3
Municipal bonds	3		—		43		1		—		39
Total Other Investments(a)	3		—		44		1		—		42
Total Investments	$	219	$	2	$	850	$	305	$	3	$	803

(a) These amounts are recorded in Other within Investments and Other Assets on the Consolidated Balance Sheets.

Schedule of Maturity Dates for Debt Securities

The table below summarizes the maturity date for debt securities.

(in millions)	December 31, 2014
Due in one year or less	$	147
Due after one through five years	210
Due after five through 10 years	48
Due after 10 years	92
Total	$	497

Schedule of Realized Gain (Loss)

Realized gains and losses, which were determined on a specific identification basis, from sales of available-for-sale securities were as follows.

	Years Ended December 31,
(in millions)	2014		2013		2012
Realized gains	$	138	$	32	$	13
Realized losses	5		20		9

Duke Energy Indiana [Member]

Schedule of Available-for-sale Securities [Line Items]

Available-For-Sale Investments

The following table presents the estimated fair value of investments in available-for-sale securities.

	December 31, 2014						December 31, 2013
(in millions)	Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Estimated Fair Value		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Estimated Fair Value
Other Investments
Cash and cash equivalents	$	—	$	—	$	—	$	—	$	—	$	1
Equity securities	28		—		71		24		—		65
Municipal bonds	—		1		30		—		1		28
Total Other Investments(a)	28		1		101		24		1		94
Total Investments	$	28	$	1	$	101	$	24	$	1	$	94

(a) These amounts are recorded in Other within Investments and Other Assets on the Consolidated Balance Sheets.

Schedule of Maturity Dates for Debt Securities

The table below summarizes the maturity date for debt securities.

(in millions)	December 31, 2014
Due in one year or less	$	1
Due after one through five years	17
Due after five through 10 years	8
Due after 10 years	4
Total	$	30