Investments in Debt and Equity Securities (Tables)

3 Months Ended

Mar. 31, 2015

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

Available-for-sale Securities

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

	March 31, 2015						December 31, 2014
(in millions)	Gross Unrealized Holding Gains		Gross Unrealized Holding Losses(b)		Estimated Fair Value(c)		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses(b)		Estimated Fair Value
NDTF
Cash and cash equivalents	$	—	$	—	$	106	$	—	$	—	$	136
Equity securities	1,916		28		3,643		1,926		29		3,650
Corporate debt securities	19		1		482		14		2		454
Municipal bonds	7		2		227		5		—		184
U.S. government bonds	24		1		864		19		2		978
Other debt securities	2		2		148		1		2		147
Total NDTF(d)	$	1,968	$	34	$	5,470	$	1,965	$	35	$	5,549
Other Investments
Cash and cash equivalents	$	—	$	—	$	29	$	—	$	—	$	15
Equity securities	36		—		98		34		—		96
Corporate debt securities	3		—		81		1		1		58
Municipal bonds	3		1		75		3		1		76
U.S. government bonds	—		—		45		—		—		27
Other debt securities	1		2		83		1		1		80
Total Other Investments(a)	$	43	$	3	$	411	$	39	$	3	$	352
Total Investments	$	2,011	$	37	$	5,881	$	2,004	$	38	$	5,901

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

(b) Substantially all these amounts represent other-than-temporary impairments on investments within Investment Trusts that have been recognized immediately as a regulatory asset.

(c) These amounts exclude net pending trade receivables of $107 million as of March 31, 2015.

Investments Classified by Contractual Maturity Date

The table below summarizes the maturity date for debt securities.

(in millions)	March 31, 2015
Due in one year or less	$	110
Due after one through five years	603
Due after five through 10 years	488
Due after 10 years	804
Total	$	2,005

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.

	Three Months Ended March 31,
(in millions)	2015		2014
Realized gains	$	102	$	31
Realized losses	14		4

Duke Energy Carolinas [Member]

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

Available-for-sale Securities

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

	March 31, 2015						December 31, 2014
(in millions)	Gross Unrealized Holding Gains		Gross Unrealized Holding Losses(b)		Estimated Fair Value(c)		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses(b)		Estimated Fair Value
NDTF
Cash and cash equivalents	$	—	$	—	$	42	$	—	$	—	$	51
Equity securities	1,076		16		2,127		1,102		17		2,162
Corporate debt securities	11		1		329		8		2		316
Municipal bonds	2		1		90		1		—		62
U.S. government bonds	8		1		296		7		1		308
Other debt securities	2		2		128		1		2		133
Total NDTF	$	1,099	$	21	$	3,012	$	1,119	$	22	$	3,032
Other Investments
Other debt securities	$	—	$	1	$	3	$	—	$	1	$	3
Total Other Investments(a)	$	—	$	1	$	3	$	—	$	1	$	3
Total Investments	$	1,099	$	22	$	3,015	$	1,119	$	23	$	3,035

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

(b) Substantially all these amounts represent other-than-temporary impairments on investments within Investment Trusts that have been recognized immediately as a regulatory asset.

(c) These amounts exclude net pending trade receivables of $107 million as of March 31, 2015.

Investments Classified by Contractual Maturity Date

The table below summarizes the maturity date for debt securities.

(in millions)	March 31, 2015
Due in one year or less	$	5
Due after one through five years	177
Due after five through 10 years	257
Due after 10 years	407
Total	$	846

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.

	Three Months Ended March 31,
(in millions)	2015		2014
Realized gains	$	90	$	23
Realized losses	12		1

Progress Energy [Member]

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

Available-for-sale Securities

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

	March 31, 2015						December 31, 2014
(in millions)	Gross Unrealized Holding Gains		Gross Unrealized Holding Losses(b)		Estimated Fair Value		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses(b)		Estimated Fair Value
NDTF
Cash and cash equivalents	$	—	$	—	$	64	$	—	$	—	$	85
Equity securities	840		12		1,516		824		12		1,488
Corporate debt securities	8		—		153		6		—		138
Municipal bonds	5		1		137		4		—		122
U.S. government bonds	16		—		568		12		1		670
Other debt securities	—		—		20		—		—		14
Total NDTF(c)	$	869	$	13	$	2,458	$	846	$	13	$	2,517
Other Investments
Cash and cash equivalents	$	—	$	—	$	18	$	—	$	—	$	15
Municipal bonds	3		—		42		3		—		43
Total Other Investments(a)	$	3	$	—	$	60	$	3	$	—	$	58
Total Investments	$	872	$	13	$	2,518	$	849	$	13	$	2,575

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

(b)

Investments Classified by Contractual Maturity Date

The table below summarizes the maturity date for debt securities.

(in millions)	March 31, 2015
Due in one year or less	$	84
Due after one through five years	350
Due after five through 10 years	160
Due after 10 years	326
Total	$	920

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.

	Three Months Ended March 31,
(in millions)	2015		2014
Realized gains	$	12	$	7
Realized losses	1		2

Duke Energy Progress [Member]

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

Available-for-sale Securities

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

	March 31, 2015						December 31, 2014
(in millions)	Gross Unrealized Holding Gains		Gross Unrealized Holding Losses(b)		Estimated Fair Value		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses(b)		Estimated Fair Value
NDTF
Cash and cash equivalents	$	—	$	—	$	40	$	—	$	—	$	50
Equity securities	626		10		1,194		612		10		1,171
Corporate debt securities	6		—		107		5		—		97
Municipal bonds	5		1		135		4		—		120
U.S. government bonds	10		—		251		9		1		265
Other debt securities	—		—		12		—		—		8
Total NDTF	$	647	$	11	$	1,739	$	630	$	11	$	1,711
Other Investments
Cash and cash equivalents	$	—	$	—	$	1	$	—	$	—	$	—
Total Other Investments(a)	$	—	$	—	$	1	$	—	$	—	$	—
Total Investments	$	647	$	11	$	1,740	$	630	$	11	$	1,711

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

(b)

Investments Classified by Contractual Maturity Date

The table below summarizes the maturity date for debt securities.

(in millions)	March 31, 2015
Due in one year or less	$	12
Due after one through five years	147
Due after five through 10 years	113
Due after 10 years	233
Total	$	505

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.

	Three Months Ended March 31,
(in millions)	2015		2014
Realized gains	$	9	$	6
Realized losses	1		2

Duke Energy Florida [Member]

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

Available-for-sale Securities

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

	March 31, 2015						December 31, 2014
(in millions)	Gross Unrealized Holding Gains		Gross Unrealized Holding Losses(b)		Estimated Fair Value		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses(b)		Estimated Fair Value
NDTF
Cash and cash equivalents	$	—	$	—	$	24	$	—	$	—	$	35
Equity securities	214		2		322		212		2		317
Corporate debt securities	2		—		46		1		—		41
Municipal bonds	—		—		2		—		—		2
U.S. government bonds	6		—		317		3		—		405
Other debt securities	—		—		8		—		—		6
Total NDTF	$	222	$	2	$	719	$	216	$	2	$	806
Other Investments
Cash and cash equivalents	$	—	$	—	$	2	$	—	$	—	$	1
Municipal bonds	3		—		42		3		—		43
Total Other Investments(a)	$	3	$	—	$	44	$	3	$	—	$	44
Total Investments	$	225	$	2	$	763	$	219	$	2	$	850

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

(b)

Investments Classified by Contractual Maturity Date

The table below summarizes the maturity date for debt securities.

(in millions)	March 31, 2015
Due in one year or less	$	72
Due after one through five years	203
Due after five through 10 years	47
Due after 10 years	93
Total	$	415

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.

	Three Months Ended March 31,
(in millions)	2015		2014
Realized gains	$	3	$	1
Realized losses	—		1

Duke Energy Indiana [Member]

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

Available-for-sale Securities

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

	March 31, 2015						December 31, 2014
(in millions)	Gross Unrealized Holding Gains		Gross Unrealized Holding Losses(b)		Estimated Fair Value		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses(b)		Estimated Fair Value
Other Investments
Equity securities	$	30	$	—	$	73	$	28	$	—	$	71
Municipal bonds	—		1		30		—		1		30
Total Other Investments(a)	$	30	$	1	$	103	$	28	$	1	$	101
Total Investments	$	30	$	1	$	103	$	28	$	1	$	101

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

(b)

Investments Classified by Contractual Maturity Date

The table below summarizes the maturity date for debt securities.

(in millions)	March 31, 2015
Due in one year or less	$	2
Due after one through five years	17
Due after five through 10 years	8
Due after 10 years	3
Total	$	30