v3.7.0.1

Investments in Debt and Equity Securities (Tables)

3 Months Ended

Mar. 31, 2017

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, 2017												December 31, 2016
	Gross				Gross								Gross				Gross
	Unrealized				Unrealized				Estimated				Unrealized				Unrealized				Estimated
	Holding				Holding				Fair				Holding				Holding				Fair
(in millions)	Gains				Losses(a)				Value				Gains				Losses(a)				Value
NDTF
Cash and cash equivalents	$	—			$	—			$	114			$	—			$	—			$	111
Equity securities	2,250				32				4,284				2,092				54				4,106
Corporate debt securities	10				5				576				10				8				528
Municipal bonds	3				6				336				3				10				331
U.S. government bonds	10				8				949				10				8				984
Other debt securities	—				3				132				—				3				124
Total NDTF	$	2,273			$	54			$	6,391			$	2,115			$	83			$	6,184
Other Investments
Cash and cash equivalents	$	—			$	—			$	18			$	—			$	—			$	25
Equity securities	44				—				106				38				—				104
Corporate debt securities	1				—				60				1				1				66
Municipal bonds	2				1				84				2				1				82
U.S. government bonds	—				—				43				—				1				51
Other debt securities	—				2				42				—				2				42
Total Other Investments(b)	$	47			$	3			$	353			$	41			$	5			$	370
Total Investments	$	2,320			$	57			$	6,744			$	2,156			$	88			$	6,554

(a) Substantially all amounts are considered OTTIs on investments within Investment Trusts that have been recognized immediately as a regulatory asset.

(b) These amounts are recorded in Other within Other Noncurrent Assets on the Condensed Consolidated Balance Sheets.

Investments Classified by Contractual Maturity Date

The table below summarizes the maturity date for debt securities.

(in millions)	March 31, 2017
Due in one year or less	$	82
Due after one through five years	640
Due after five through 10 years	514
Due after 10 years	986
Total	$	2,222

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)	2017				2016
Realized gains	$	93			$	54
Realized losses	62				50

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, 2017												December 31, 2016
	Gross				Gross								Gross				Gross
	Unrealized				Unrealized				Estimated				Unrealized				Unrealized				Estimated
	Holding				Holding				Fair				Holding				Holding				Fair
(in millions)	Gains				Losses(a)				Value				Gains				Losses(a)				Value
NDTF
Cash and cash equivalents	$	—			$	—			$	20			$	—			$	—			$	18
Equity securities	1,229				15				2,366				1,157				28				2,245
Corporate debt securities	5				4				388				5				6				354
Municipal bonds	1				1				67				1				2				67
U.S. government bonds	3				5				431				2				5				458
Other debt securities	—				3				120				—				3				116
Total NDTF	$	1,238			$	28			$	3,392			$	1,165			$	44			$	3,258
Other Investments
Other debt securities	$	—			$	1			$	3			$	—			$	1			$	3
Total Other Investments(b)	$	—			$	1			$	3			$	—			$	1			$	3
Total Investments	$	1,238			$	29			$	3,395			$	1,165			$	45			$	3,261

(a) Substantially all amounts are considered OTTIs on investments within Investment Trusts that have been recognized immediately as a regulatory asset.

(b) These amounts are recorded in Other within Other Noncurrent Assets on the Condensed Consolidated Balance Sheets.

Investments Classified by Contractual Maturity Date

The table below summarizes the maturity date for debt securities.

(in millions)	March 31, 2017
Due in one year or less	$	2
Due after one through five years	221
Due after five through 10 years	269
Due after 10 years	517
Total	$	1,009

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)	2017				2016
Realized gains	$	66			$	34
Realized losses	40				37

Progress Energy [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, 2017												December 31, 2016
	Gross				Gross								Gross				Gross
	Unrealized				Unrealized				Estimated				Unrealized				Unrealized				Estimated
	Holding				Holding				Fair				Holding				Holding				Fair
(in millions)	Gains				Losses(a)				Value				Gains				Losses(a)				Value
NDTF
Cash and cash equivalents	$	—			$	—			$	94			$	—			$	—			$	93
Equity securities	1,021				17				1,918				935				26				1,861
Corporate debt securities	5				1				188				5				2				174
Municipal bonds	2				5				269				2				8				264
U.S. government bonds	7				3				518				8				3				526
Other debt securities	—				—				12				—				—				8
Total NDTF	$	1,035			$	26			$	2,999			$	950			$	39			$	2,926
Other Investments
Cash and cash equivalents	$	—			$	—			$	12			$	—			$	—			$	21
Municipal bonds	2				—				46				2				—				44
Total Other Investments(b)	$	2			$	—			$	58			$	2			$	—			$	65
Total Investments	$	1,037			$	26			$	3,057			$	952			$	39			$	2,991

(a) Substantially all amounts are considered OTTIs on investments within Investment Trusts that have been recognized immediately as a regulatory asset.

(b) These amounts are recorded in Other within Other Noncurrent Assets on the Condensed Consolidated Balance Sheets.

Investments Classified by Contractual Maturity Date

The table below summarizes the maturity date for debt securities.

(in millions)	March 31, 2017
Due in one year or less	$	72
Due after one through five years	355
Due after five through 10 years	189
Due after 10 years	417
Total	$	1,033

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)	2017				2016
Realized gains	$	27			$	19
Realized losses	21				13

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, 2017												December 31, 2016
	Gross				Gross								Gross				Gross
	Unrealized				Unrealized				Estimated				Unrealized				Unrealized				Estimated
	Holding				Holding				Fair				Holding				Holding				Fair
(in millions)	Gains				Losses(a)				Value				Gains				Losses(a)				Value
NDTF
Cash and cash equivalents	$	—			$	—			$	43			$	—			$	—			$	45
Equity securities	772				13				1,541				704				21				1,505
Corporate debt securities	4				1				131				4				1				120
Municipal bonds	2				5				268				2				8				263
U.S. government bonds	5				2				284				5				2				275
Other debt securities	—				—				7				—				—				5
Total NDTF	$	783			$	21			$	2,274			$	715			$	32			$	2,213
Other Investments
Cash and cash equivalents	$	—			$	—			$	1			$	—			$	—			$	1
Total Other Investments(b)	$	—			$	—			$	1			$	—			$	—			$	1
Total Investments	$	783			$	21			$	2,275			$	715			$	32			$	2,214

(a) Substantially all amounts are considered OTTIs on investments within Investment Trusts that have been recognized immediately as a regulatory asset.

(b) These amounts are recorded in Other within Other Noncurrent Assets on the Condensed Consolidated Balance Sheets.

Investments Classified by Contractual Maturity Date

The table below summarizes the maturity date for debt securities.

(in millions)	March 31, 2017
Due in one year or less	$	17
Due after one through five years	215
Due after five through 10 years	142
Due after 10 years	316
Total	$	690

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)	2017				2016
Realized gains	$	24			$	15
Realized losses	19				11

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, 2017												December 31, 2016
	Gross				Gross								Gross				Gross
	Unrealized				Unrealized				Estimated				Unrealized				Unrealized				Estimated
	Holding				Holding				Fair				Holding				Holding				Fair
(in millions)	Gains				Losses(a)				Value				Gains				Losses(a)				Value
NDTF
Cash and cash equivalents	$	—			$	—			$	51			$	—			$	—			$	48
Equity securities	249				4				377				231				5				356
Corporate debt securities	1				—				57				1				1				54
Municipal bonds	—				—				1				—				—				1
U.S. government bonds	2				1				234				3				1				251
Other debt securities	—				—				5				—				—				3
Total NDTF(b)	$	252			$	5			$	725			$	235			$	7			$	713
Other Investments
Cash and cash equivalents	$	—			$	—			$	1			$	—			$	—			$	4
Municipal bonds	2				—				46				2				—				44
Total Other Investments(c)	$	2			$	—			$	47			$	2			$	—			$	48
Total Investments	$	254			$	5			$	772			$	237			$	7			$	761

(a) Substantially all amounts are considered OTTIs on investments within Investment Trusts that have been recognized immediately as a regulatory asset.

(b) During the three months ended March 31, 2017, Duke Energy Florida continued to receive reimbursements from the NDTF for costs related to ongoing commissioning activity of the Crystal River Unit 3 nuclear plant.

(c) These amounts are recorded in Other within Other Noncurrent Assets on the Condensed Consolidated Balance Sheets.

Investments Classified by Contractual Maturity Date

The table below summarizes the maturity date for debt securities.

(in millions)	March 31, 2017
Due in one year or less	$	55
Due after one through five years	140
Due after five through 10 years	47
Due after 10 years	101
Total	$	343

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)	2017				2016
Realized gains	$	3			$	4
Realized losses	2				2

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, 2017												December 31, 2016
	Gross				Gross								Gross				Gross
	Unrealized				Unrealized				Estimated				Unrealized				Unrealized				Estimated
	Holding				Holding				Fair				Holding				Holding				Fair
(in millions)	Gains				Losses(a)				Value				Gains				Losses(a)				Value
Other Investments
Equity securities	$	38			$	—			$	84			$	33			$	—			$	79
Corporate debt securities	—				—				2				—				—				2
Municipal bonds	—				1				28				—				1				28
U.S. government bonds	—				—				1				—				—				1
Total Other Investments(b)	$	38			$	1			$	115			$	33			$	1			$	110
Total Investments	$	38			$	1			$	115			$	33			$	1			$	110

(a) Substantially all amounts are considered OTTIs on investments within Investment Trusts that have been recognized immediately as a regulatory asset.

(b) These amounts are recorded in Other within Other Noncurrent Assets on the Condensed Consolidated Balance Sheets.

Investments Classified by Contractual Maturity Date

The table below summarizes the maturity date for debt securities.

(in millions)	March 31, 2017
Due in one year or less	$	2
Due after one through five years	15
Due after five through 10 years	9
Due after 10 years	5
Total	$	31

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