Employee Benefit Plans

12 Months Ended

Dec. 31, 2017

Retirement Benefits [Abstract]

Employee Benefit Plans

EMPLOYEE BENEFIT PLANS

DEFINED BENEFIT RETIREMENT PLANS

Duke Energy and certain subsidiaries maintain, and the Subsidiary Registrants participate in, qualified, non-contributory defined benefit retirement plans. The Duke Energy plans cover most employees using a cash balance formula. Under a cash balance formula, a plan participant accumulates a retirement benefit consisting of pay credits based upon a percentage of current eligible earnings, age or age and years of service and interest credits. Certain employees are eligible for benefits that use a final average earnings formula. Under these final average earnings formulas, a plan participant accumulates a retirement benefit equal to the sum of percentages of their (i) highest three-year, four-year, or five-year average earnings, (ii) highest three-year, four-year, or five-year average earnings in excess of covered compensation per year of participation (maximum of 35 years), (iii) highest three-year average earnings times years of participation in excess of 35 years. Duke Energy also maintains, and the Subsidiary Registrants participate in, non-qualified, non-contributory defined benefit retirement plans that cover certain executives. The qualified and non-qualified, non-contributory defined benefit plans are closed to new participants.

Duke Energy approved plan amendments to restructure its qualified non-contributory defined benefit retirement plans, effective January 1, 2018. The restructuring involved (i) the spin-off of the majority of inactive participants from two plans into a separate inactive plan and (ii) the merger of the active participant portions of such plans, along with a pension plan acquired as part of the Piedmont transaction, into a single active plan. Benefits offered to the plan participants remain unchanged except that the Piedmont plan's final average earnings formula was frozen as of December 31, 2017, and affected participants were moved into the active plan's cash balance formula. Actuarial gains and losses associated with the Inactive Plan will be amortized over the remaining life expectancy of the inactive participants. The longer amortization period is expected to lower Duke Energy's 2018 pretax qualified pension plan expense by approximately $33 million.

Duke Energy uses a December 31 measurement date for its defined benefit retirement plan assets and obligations.

Net periodic benefit costs disclosed in the tables below represent the cost of the respective benefit plan for the periods presented. However, portions of the net periodic benefit costs disclosed in the tables below have been capitalized as a component of property, plant and equipment. Amounts presented in the tables below for the Subsidiary Registrants represent the amounts of pension and other post-retirement benefit cost allocated by Duke Energy for employees of the Subsidiary Registrants. Additionally, the Subsidiary Registrants are allocated their proportionate share of pension and post-retirement benefit cost for employees of Duke Energy’s shared services affiliate that provide support to the Subsidiary Registrants. These allocated amounts are included in the governance and shared service costs discussed in Note 13.

Duke Energy’s policy is to fund amounts on an actuarial basis to provide assets sufficient to meet benefit payments to be paid to plan participants. The following table includes information related to the Duke Energy Registrants’ contributions to its qualified defined benefit pension plans.

			Duke				Duke		Duke		Duke		Duke
	Duke		Energy		Progress		Energy		Energy		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont(a)
Anticipated Contributions:
Total anticipated 2018 contributions	$	148	$	46	$	45	$	25	$	20	$	—	$	8	$	7
Contributions made January 2, 2018	141		46		45		25		20		—		8		—
Contributions to be made in 2018	$	7	$	—	$	—	$	—	$	—	$	—	$	—	$	7
Contributions Made:
2017	$	19	$	—	$	—	$	—	$	—	$	4	$	—	$	11
2016	155		43		43		24		20		5		9
2015	302		91		83		42		40		8		19

(a) Piedmont contributed $10 million to its U.S. qualified defined benefit pension plan during the two months ended December 31, 2016, and for each of the years ended October 31, 2016, and 2015, respectively.

QUALIFIED PENSION PLANS

Components of Net Periodic Pension Costs

	Year Ended December 31, 2017
				Duke						Duke			Duke			Duke			Duke
	Duke			Energy			Progress			Energy			Energy			Energy			Energy
(in millions)	Energy			Carolinas			Energy			Progress			Florida			Ohio			Indiana			Piedmont
Service cost	$	159		$	48		$	45		$	26		$	19		$	4		$	9		$	10
Interest cost on projected benefit obligation	328			79			100			47			53			18			26			14
Expected return on plan assets	(545		)	(142		)	(167		)	(82		)	(85		)	(27		)	(42		)	(24		)
Amortization of actuarial loss	146			31			52			23			29			5			12			11
Amortization of prior service credit	(24		)	(8		)	(3		)	(2		)	(1		)	(1		)	(2		)	(2		)
Settlement charge	12			—			—			—			—			—			—			12
Other	8			2			2			1			1			—			1			1
Net periodic pension costs(a)(b)	$	84		$	10		$	29		$	13		$	16		$	(1	)	$	4		$	22

	Year Ended December 31, 2016
				Duke						Duke			Duke			Duke			Duke
	Duke			Energy			Progress			Energy			Energy			Energy			Energy
(in millions)	Energy			Carolinas			Energy			Progress			Florida			Ohio			Indiana
Service cost	$	147		$	48		$	42		$	24		$	19		$	4		$	9
Interest cost on projected benefit obligation	335			86			106			49			55			19			28
Expected return on plan assets	(519		)	(142		)	(168		)	(82		)	(84		)	(27		)	(42		)
Amortization of actuarial loss	134			33			51			23			29			4			11
Amortization of prior service (credit)	(17		)	(8		)	(3		)	(2		)	(1		)	—			(1		)
Settlement charge	3			—			—			—			—			—			—
Other	8			2			3			1			1			1			1
Net periodic pension costs(a)(b)	$	91		$	19		$	31		$	13		$	19		$	1		$	6

	Year Ended December 31, 2015
				Duke						Duke			Duke			Duke			Duke
	Duke			Energy			Progress			Energy			Energy			Energy			Energy
(in millions)	Energy			Carolinas			Energy			Progress			Florida			Ohio			Indiana
Service cost	$	159		$	50		$	44		$	23		$	20		$	4		$	10
Interest cost on projected benefit obligation	324			83			104			48			54			18			27
Expected return on plan assets	(516		)	(139		)	(171		)	(79		)	(87		)	(26		)	(42		)
Amortization of actuarial loss	166			39			65			33			31			7			13
Amortization of prior service (credit) cost	(15		)	(7		)	(3		)	(2		)	(1		)	—			1
Other	8			2			3			1			1			—			1
Net periodic pension costs(a)(b)	$	126		$	28		$	42		$	24		$	18		$	3		$	10

(a) Duke Energy amounts exclude $7 million, $8 million and $9 million for the years ended December 2017, 2016 and 2015, respectively, of regulatory asset amortization resulting from purchase accounting adjustments associated with Duke Energy's merger with Cinergy in April 2006.

(b) Duke Energy Ohio amounts exclude $3 million, $4 million and $4 million for the years ended December 2017, 2016 and 2015, respectively, of regulatory asset amortization resulting from purchase accounting adjustments associated with Duke Energy's merger with Cinergy in April 2006.

	Piedmont
	Two Months Ended			Years Ended October 31,
(in millions)	December 31, 2016			2016			2015
Service cost	$	2		$	11		$	11
Interest cost on projected benefit obligation	2			9			12
Expected return on plan assets	(4		)	(24		)	(24		)
Amortization of actuarial loss	2			8			9
Amortization of prior service credit	(1		)	(2		)	(2		)
Settlement charge	3			—			—
Net periodic pension costs	$	4		$	2		$	6

Amounts Recognized in Accumulated Other Comprehensive Income and Regulatory Assets

	Year Ended December 31, 2017
				Duke						Duke			Duke			Duke		Duke
	Duke			Energy			Progress			Energy			Energy			Energy		Energy
(in millions)	Energy			Carolinas			Energy			Progress			Florida			Ohio		Indiana			Piedmont
Regulatory assets, net (decrease) increase	$	(212	)	$	(70	)	$	(49	)	$	(37	)	$	(11	)	$	9	$	(19	)	$	(64	)
Accumulated other comprehensive loss (income)
Deferred income tax expense	$	—		—			3			—			—			—		—			—
Prior year service cost arising during the year	1			—			—			—			—			—		—			—
Amortization of prior year actuarial losses	(7		)	—			(7		)	—			—			—		—			—
Net amount recognized in accumulated other comprehensive income	$	(6	)	$	—		$	(4	)	$	—		$	—		$	—	$	—		$	—

	Year Ended December 31, 2016
				Duke					Duke		Duke		Duke		Duke
	Duke			Energy		Progress			Energy		Energy		Energy		Energy
(in millions)	Energy			Carolinas		Energy			Progress		Florida		Ohio		Indiana
Regulatory assets, net increase	$	214		$	4	$	34		$	18	$	16	$	2	$	9
Accumulated other comprehensive (income) loss
Deferred income tax expense	$	4		$	—	$	—		$	—	$	—	$	—	$	—
Prior year service credit arising during the year	(2		)	—		—			—		—		—		—
Amortization of prior year actuarial losses	(7		)	—		(1		)	—		—		—		—
Net amount recognized in accumulated other comprehensive income	$	(5	)	$	—	$	(1	)	$	—	$	—	$	—	$	—

Piedmont's regulatory asset net increase was $34 million, $35 million and $20 million for the two months ended December 31, 2016, and for the years ended October 31, 2016, and 2015, respectively.

Reconciliation of Funded Status to Net Amount Recognized

	Year Ended December 31, 2017
				Duke						Duke			Duke			Duke			Duke
	Duke			Energy			Progress			Energy			Energy			Energy			Energy
(in millions)	Energy			Carolinas			Energy			Progress			Florida			Ohio			Indiana			Piedmont
Change in Projected Benefit Obligation
Obligation at prior measurement date	$	8,131		$	1,952		$	2,512		$	1,158		$	1,323		$	447		$	658		$	344
Service cost	159			48			45			26			19			4			9			10
Interest cost	328			79			100			47			53			18			26			14
Actuarial loss	455			68			158			57			99			35			26			38
Transfers	—			27			(32		)	(2		)	(15		)	12			—			—
Plan amendments	(61		)	—			—			—			—						—			(61		)
Benefits paid	(537		)	(145		)	(146		)	(75		)	(69		)	(37		)	(50		)	(5		)
Benefits paid - settlements	(27		)	—			—			—			—			—			—			(27		)
Obligation at measurement date	$	8,448		$	2,029		$	2,637		$	1,211		$	1,410		$	479		$	669		$	313
Accumulated Benefit Obligation at measurement date	$	8,369		$	2,029		$	2,601		$	1,211		$	1,375		$	468		$	652		$	313
Change in Fair Value of Plan Assets
Plan assets at prior measurement date	$	8,531		$	2,225		$	2,675		$	1,290		$	1,352		$	428		$	657		$	346
Employer contributions	19			—			—			—			—			4			—			11
Actual return on plan assets	1,017			265			317			153			161			51			77			43
Benefits paid	(537		)	(145		)	(146		)	(75		)	(69		)	(37		)	(50		)	(5		)
Benefits paid - settlements	(27		)	—			—			—			—			—			—			(27		)
Transfers	—			27			(32		)	(2		)	(15		)	12			—			—
Plan assets at measurement date	$	9,003		$	2,372		$	2,814		$	1,366		$	1,429		$	458		$	684		$	368
Funded status of plan	$	555		$	343		$	177		$	155		$	19		$	(21	)	$	15		$	55

	Year Ended December 31, 2016
				Duke						Duke			Duke			Duke			Duke
	Duke			Energy			Progress			Energy			Energy			Energy			Energy
(in millions)	Energy			Carolinas			Energy			Progress			Florida			Ohio			Indiana
Change in Projected Benefit Obligation
Obligation at prior measurement date	$	7,727		$	1,995		$	2,451		$	1,143		$	1,276		$	453		$	649
Obligation assumed from acquisition	352			—			—			—			—			—			—
Service cost	147			48			42			24			19			4			9
Interest cost	335			86			106			49			55			19			28
Actuarial loss	307			46			111			52			57			13			41
Transfers	—			14			(3		)	(3		)	—			(3		)	—
Plan amendments	(52		)	(3		)	—			—			—			(3		)	(15		)
Benefits paid	(679		)	(234		)	(195		)	(107		)	(84		)	(36		)	(54		)
Impact of settlements	(6		)	—			—			—			—			—			—
Obligation at measurement date	$	8,131		$	1,952		$	2,512		$	1,158		$	1,323		$	447		$	658
Accumulated Benefit Obligation at measurement date	$	8,006		$	1,952		$	2,479		$	1,158		$	1,290		$	436		$	649
Change in Fair Value of Plan Assets
Plan assets at prior measurement date	$	8,136		$	2,243		$	2,640		$	1,284		$	1,321		$	433		$	655
Assets received from acquisition	343			—			—			—			—			—			—
Employer contributions	155			43			43			24			20			5			9
Actual return on plan assets	582			159			190			92			95			29			47
Benefits paid	(679		)	(234		)	(195		)	(107		)	(84		)	(36		)	(54		)
Impact of settlements	(6		)	—			—			—			—			—			—
Transfers	—			14			(3		)	(3		)	—			(3		)	—
Plan assets at measurement date	$	8,531		$	2,225		$	2,675		$	1,290		$	1,352		$	428		$	657
Funded status of plan	$	400		$	273		$	163		$	132		$	29		$	(19	)	$	(1	)

	Piedmont
	Two Months Ended			Years Ended
(in millions)	December 31, 2016			October 31, 2016
Change in Projected Benefit Obligation
Obligation at prior measurement date	$	352		$	312
Service cost	2			11
Interest cost	2			9
Actuarial gain	(5		)	34
Benefits paid	(1		)	(14		)
Impact of settlements	(6		)	—
Obligation at measurement date	$	344		$	352
Accumulated Benefit Obligation at measurement date	$	289		$	296
Change in Fair Value of Plan Assets
Plan assets at prior measurement date	$	343		$	329
Employer contributions	10			10
Actual return on plan assets	—			18
Benefits paid	(1		)	(14		)
Impact of settlements	(6		)	—
Plan assets at measurement date	$	346		$	343
Funded status of plan	$	2		$	(9	)

Amounts Recognized in the Consolidated Balance Sheets

	December 31, 2017
				Duke						Duke			Duke			Duke			Duke
	Duke			Energy			Progress			Energy			Energy			Energy			Energy
(in millions)	Energy			Carolinas			Energy			Progress			Florida			Ohio			Indiana			Piedmont
Prefunded pension(a)	$	680		$	343		$	245		$	155		$	87		$	8		$	16		$	55
Noncurrent pension liability(b)	$	125		$	—		$	68		$	—		$	68		$	29		$	1		$	—
Net asset (liability) recognized	$	555		$	343		$	177		$	155		$	19		$	(21	)	$	15		$	55
Regulatory assets	$	1,886		$	406		$	756		$	341		$	415		$	90		$	152		$	73
Accumulated other comprehensive (income) loss
Deferred income tax benefit	$	(41	)	$	—		$	(3	)	$	—		$	—		$	—		$	—		$	—
Prior service credit	(5		)	—			—			—			—			—			—			—
Net actuarial loss	116			—			9			—			—			—			—			—
Net amounts recognized in accumulated other comprehensive loss	$	70		$	—		$	6		$	—		$	—		$	—		$	—		$	—
Amounts to be recognized in net periodic pension costs in the next year
Unrecognized net actuarial loss	$	132		$	29		$	44		$	21		$	23		$	5		$	7		$	11
Unrecognized prior service credit	(32		)	(8		)	(3		)	(2		)	(1		)	—			(2		)	(9		)

	December 31, 2016
				Duke						Duke			Duke			Duke			Duke
	Duke			Energy			Progress			Energy			Energy			Energy			Energy
(in millions)	Energy			Carolinas			Energy			Progress			Florida			Ohio			Indiana			Piedmont
Prefunded pension(a)	$	518		$	273		$	225		$	132		$	91		$	6		$	—		3
Noncurrent pension liability(b)	$	118		$	—		$	62		$	—		$	62		$	25		$	1		—
Net asset recognized	$	400		$	273		$	163		$	132		$	29		$	(19	)	$	(1	)	$	3
Regulatory assets	$	2,098		$	476		$	805		$	378		$	426		$	81		$	171		$	137
Accumulated other comprehensive (income) loss
Deferred income tax benefit	$	(41	)	$	—		$	(6	)	$	—		$	—		$	—		$	—		$	—
Prior service credit	(6		)	—			—			—			—			—			—			—
Net actuarial loss	123			—			16			—			—			—			—			—
Net amounts recognized in accumulated other comprehensive loss	$	76		$	—		$	10		$	—		$	—		$	—		$	—		$	—
Amounts to be recognized in net periodic pension costs in the next year
Unrecognized net actuarial loss	$	147		$	31		$	52		$	23		$	29		$	5		$	8		$	13
Unrecognized prior service credit	$	(24	)	$	(8	)	$	(3	)	$	(2	)	$	(1	)	$	—		$	(2	)	$	(2	)

(a) Included in Other within Other Noncurrent Assets on the Consolidated Balance Sheets.

(b) Included in Accrued pension and other post-retirement benefit costs on the Consolidated Balance Sheets.

Information for Plans with Accumulated Benefit Obligation in Excess of Plan Assets

	December 31, 2017
					Duke		Duke
	Duke		Progress		Energy		Energy
(in millions)	Energy		Energy		Florida		Ohio
Projected benefit obligation	$	1,386	$	718	$	718	$	337
Accumulated benefit obligation	1,326		683		683		326
Fair value of plan assets	1,260		650		650		308

	December 31, 2016
					Duke		Duke
	Duke		Progress		Energy		Energy
(in millions)	Energy		Energy		Florida		Ohio
Projected benefit obligation	$	1,299	$	665	$	665	$	311
Accumulated benefit obligation	1,239		633		633		299
Fair value of plan assets	1,182		604		604		286

Assumptions Used for Pension Benefits Accounting

The discount rate used to determine the current year pension obligation and following year’s pension expense is based on a bond selection-settlement portfolio approach. This approach develops a discount rate by selecting a portfolio of high quality corporate bonds that generate sufficient cash flow to provide for projected benefit payments of the plan. The selected bond portfolio is derived from a universe of non-callable corporate bonds rated Aa quality or higher. After the bond portfolio is selected, a single interest rate is determined that equates the present value of the plan’s projected benefit payments discounted at this rate with the market value of the bonds selected.

The average remaining service period of active covered employees is 13 years for Duke Energy and Duke Energy Progress, 12 years for Duke Energy Carolinas, Progress Energy, and Duke Energy Florida, 14 years for Duke Energy Ohio and Duke Energy Indiana, and nine years for Piedmont.

The following tables present the assumptions or range of assumptions used for pension benefit accounting.

	December 31,
	2017				2016				2015
Benefit Obligations
Discount rate				3.60%				4.10%				4.40%
Salary increase	3.50	%	–	4.00%	4.00	%	–	4.50%	4.00	%	–	4.40%
Net Periodic Benefit Cost
Discount rate				4.10%				4.40%				4.10%
Salary increase	4.00	%	–	4.50%	4.00	%	–	4.40%	4.00	%	–	4.40%
Expected long-term rate of return on plan assets	6.50	%	–	6.75%	6.50	%	–	6.75%				6.50%

	Piedmont
	Two Months Ended		Years Ended October 31,
	December 31, 2016		2016		2015
Benefit Obligations
Discount rate	4.10	%	3.80	%	4.34	%
Salary increase	4.50	%	4.05	%	4.07	%
Net Periodic Benefit Cost
Discount rate	3.80	%	4.34	%	4.13	%
Salary increase	4.05	%	4.07	%	3.68	%
Expected long-term rate of return on plan assets	6.75	%	7.25	%	7.50	%

Expected Benefit Payments

			Duke				Duke		Duke		Duke		Duke
	Duke		Energy		Progress		Energy		Energy		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
Years ending December 31,
2018	$	642	$	185	$	161	$	85	$	75	$	36	$	47	$	29
2019	644		185		164		86		77		36		46		26
2020	661		195		172		90		80		36		44		24
2021	666		194		175		93		81		37		44		24
2022	672		197		176		92		83		36		44		23
2023-2027	3,099		865		888		449		435		166		210		103

NON-QUALIFIED PENSION PLANS

Components of Net Periodic Pension Costs

	Year Ended December 31, 2017
				Duke				Duke		Duke		Duke		Duke
	Duke			Energy		Progress		Energy		Energy		Energy		Energy
(in millions)	Energy			Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
Service cost	$	2		$	1	$	—	$	—	$	—	$	—	$	—	$	—
Interest cost on projected benefit obligation	13			1		5		1		2		—		—		—
Amortization of actuarial loss	8			—		2		1		1		—		—		—
Amortization of prior service credit	(2		)	—		—		—		—		—		—		—
Net periodic pension costs	$	21		$	2	$	7	$	2	$	3	$	—	$	—	$	—

	Year Ended December 31, 2016
				Duke				Duke		Duke		Duke		Duke
	Duke			Energy		Progress		Energy		Energy		Energy		Energy
(in millions)	Energy			Carolinas		Energy		Progress		Florida		Ohio		Indiana
Service cost	$	2		$	—	$	—	$	—	$	—	$	—	$	—
Interest cost on projected benefit obligation	14			1		5		1		2		—		—
Amortization of actuarial loss	8			1		1		1		1		—		—
Amortization of prior service credit	(1		)	—		—		—		—		—		—
Net periodic pension costs	$	23		$	2	$	6	$	2	$	3	$	—	$	—

	Year Ended December 31, 2015
				Duke					Duke		Duke		Duke		Duke
	Duke			Energy		Progress			Energy		Energy		Energy		Energy
(in millions)	Energy			Carolinas		Energy			Progress		Florida		Ohio		Indiana
Service cost	$	3		$	—	$	1		$	—	$	—	$	—	$	—
Interest cost on projected benefit obligation	13			1		4			1		2		—		—
Amortization of actuarial loss	6			—		2			1		2		—		1
Amortization of prior service credit	(1		)	—		(1		)	—		—		—		—
Net periodic pension costs	$	21		$	1	$	6		$	2	$	4	$	—	$	1

	Piedmont
	Years Ended October 31,
(in millions)	2016		2015
Amortization of prior service cost	$	—	$	1
Settlement charge	1		—
Net periodic pension costs	$	1	$	1

Amounts Recognized in Accumulated Other Comprehensive Income and Regulatory Assets and Liabilities

	Year Ended December 31, 2017
				Duke					Duke		Duke		Duke		Duke
	Duke			Energy			Progress		Energy		Energy		Energy		Energy
(in millions)	Energy			Carolinas			Energy		Progress		Florida		Ohio		Indiana		Piedmont
Regulatory assets, net (decrease) increase	$	5		$	(1	)	$	3	$	1	$	2	$	—	$	—	$	—
Accumulated other comprehensive (income) loss
Deferred income tax benefit	$	(1	)	$	—		$	—	$	—	$	—	$	—	$	—	$	—
Actuarial loss arising during the year	2			—			—		—		—		—		—		—
Net amount recognized in accumulated other comprehensive loss (income)	$	1		$	—		$	—	$	—	$	—	$	—	$	—	$	—

	Year Ended December 31, 2016
				Duke					Duke		Duke		Duke		Duke
	Duke			Energy			Progress		Energy		Energy		Energy		Energy
(in millions)	Energy			Carolinas			Energy		Progress		Florida		Ohio		Indiana
Regulatory assets, net (decrease) increase	$	(3	)	$	(2	)	$	2	$	1	$	1	$	—	$	(1	)
Accumulated other comprehensive (income) loss
Prior service credit arising during the year	$	(1	)	$	—		$	—	$	—	$	—	$	—	$	—
Actuarial gains arising during the year	1			—			—		—		—		—		—
Net amount recognized in accumulated other comprehensive loss (income)	$	—		$	—		$	—	$	—	$	—	$	—	$	—

Reconciliation of Funded Status to Net Amount Recognized

	Year Ended December 31, 2017
				Duke						Duke			Duke			Duke		Duke
	Duke			Energy			Progress			Energy			Energy			Energy		Energy
(in millions)	Energy			Carolinas			Energy			Progress			Florida			Ohio		Indiana		Piedmont
Change in Projected Benefit Obligation
Obligation at prior measurement date	$	332		$	14		$	114		$	33		$	46		$	4	$	3	$	4
Service cost	2			1			—			—			—			—		—		—
Interest cost	13			1			5			1			2			—		—		—
Actuarial losses (gains)	15			—			5			4			2			—		—		—
Benefits paid	(31		)	(2		)	(8		)	(3		)	(3		)	—		—		—
Obligation at measurement date	$	331		$	14		$	116		$	35		$	47		$	4	$	3	$	4
Accumulated Benefit Obligation at measurement date	$	331		$	14		$	116		$	35		$	47		$	4	$	3	$	4
Change in Fair Value of Plan Assets
Benefits paid	$	(31	)	$	(2	)	$	(8	)	$	(3	)	$	(3	)	$	—	$	—	$	—
Employer contributions	31			2			8			3			3			—		—		—
Plan assets at measurement date	$	—		$	—		$	—		$	—		$	—		$	—	$	—	$	—

	Year Ended December 31, 2016
				Duke						Duke			Duke			Duke		Duke
	Duke			Energy			Progress			Energy			Energy			Energy		Energy
(in millions)	Energy			Carolinas			Energy			Progress			Florida			Ohio		Indiana
Change in Projected Benefit Obligation
Obligation at prior measurement date	$	341		$	16		$	112		$	33		$	46		$	4	$	5
Obligation assumed from acquisition	5			—			—			—			—			—		—
Service cost	2			—			—			—			—			—		—
Interest cost	14			1			5			1			2			—		—
Actuarial losses (gains)	4			(1		)	5			2			1			—		(2		)
Plan amendments	(2		)	—			—			—			—			—
Benefits paid	(32		)	(2		)	(8		)	(3		)	(3		)	—		—
Obligation at measurement date	$	332		$	14		$	114		$	33		$	46		$	4	$	3
Accumulated Benefit Obligation at measurement date	$	332		$	14		$	114		$	33		$	46		$	4	$	3
Change in Fair Value of Plan Assets
Benefits paid	$	(32	)	$	(2	)	$	(8	)	$	(3	)	$	(3	)	—		—
Employer contributions	32			2			8			3			3			—		—
Plan assets at measurement date	$	—		$	—		$	—		$	—		$	—		$	—	$	—

	Piedmont
	Two Months Ended			Years Ended
(in millions)	December 31, 2016			October 31, 2016
Change in Projected Benefit Obligation
Obligation at prior measurement date	$	5		$	6
Actuarial gain	(1		)	—
Impact of settlements	—			(1		)
Obligation at measurement date	$	4		$	5
Accumulated Benefit Obligation at measurement date	$	—		$	5
Change in Fair Value of Plan Assets
Plan assets at prior measurement date	$	—		$	1
Impact of settlements	—			(1		)
Plan assets at measurement date	$	—		$	—

Amounts Recognized in the Consolidated Balance Sheets

	December 31, 2017
				Duke					Duke		Duke		Duke		Duke
	Duke			Energy		Progress			Energy		Energy		Energy		Energy
(in millions)	Energy			Carolinas		Energy			Progress		Florida		Ohio		Indiana		Piedmont
Current pension liability(a)	$	23		$	2	$	8		$	3	$	3	$	—	$	—	$	—
Noncurrent pension liability(b)	308			12		108			32		44		4		3		4
Total accrued pension liability	$	331		$	14	$	116		$	35	$	47	$	4	$	3	$	4
Regulatory assets	$	78		$	4	$	21		$	8	$	13	$	1	$	—	$	1
Accumulated other comprehensive (income) loss
Deferred income tax benefit	$	(4	)	$	—	$	(3	)	$	—	$	—	$	—	$	—	$	—
Prior service credit	(1		)	—		—			—		—		—		—		—
Net actuarial loss	12			—		9			—		—		—		—		—
Net amounts recognized in accumulated other comprehensive loss	$	7		$	—	$	6		$	—	$	—	$	—	$	—	$	—
Amounts to be recognized in net periodic pension expense in the next year
Unrecognized net actuarial loss	$	8		$	—	$	2		$	1	$	1	$	—	$	—	$	—
Unrecognized prior service credit	(2		)	—		—			—		—		—		—		—

	December 31, 2016
				Duke					Duke		Duke		Duke		Duke
	Duke			Energy		Progress			Energy		Energy		Energy		Energy
(in millions)	Energy			Carolinas		Energy			Progress		Florida		Ohio		Indiana		Piedmont
Current pension liability(a)	$	28		$	2	$	8		$	2	$	3	$	—	$	—	$	—
Noncurrent pension liability(b)	304			12		106			31		43		4		3		4
Total accrued pension liability	$	332		$	14	$	114		$	33	$	46	$	4	$	3	$	4
Regulatory assets	$	73		$	5	$	18		$	7	$	11	$	1	$	—	$	1
Accumulated other comprehensive (income) loss
Deferred income tax benefit	$	(3	)	$	—	$	(3	)	$	—	$	—	$	—	$	—	$	—
Prior service credit	(1		)	—		—			—		—		—		—		—
Net actuarial loss	10			—		9			—		—		—		—		—
Net amounts recognized in accumulated other comprehensive loss	$	6		$	—	$	6		$	—	$	—	$	—	$	—	$	—
Amounts to be recognized in net periodic pension expense in the next year
Unrecognized net actuarial loss	$	7		$	—	$	2		$	1	$	1	$	—	$	—	$	—
Unrecognized prior service credit	$	(2	)	$	—	$	—		$	—	$	—	$	—	$	—	$	—

(a)    Included in Other within Current Liabilities on the Consolidated Balance Sheets.

(b) Included in Accrued pension and other post-retirement benefit costs on the Consolidated Balance Sheets.

Information for Plans with Accumulated Benefit Obligation in Excess of Plan Assets

	December 31, 2017
			Duke				Duke		Duke		Duke		Duke
	Duke		Energy		Progress		Energy		Energy		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
Projected benefit obligation	$	331	$	14	$	116	$	35	$	47	$	4	$	3	$	4
Accumulated benefit obligation	331		14		116		35		47		4		3		4

	December 31, 2016
			Duke				Duke		Duke		Duke		Duke
	Duke		Energy		Progress		Energy		Energy		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
Projected benefit obligation	$	332	$	14	$	114	$	33	$	46	$	4	$	3	$	4
Accumulated benefit obligation	332		14		114		33		46		4		3		4

Assumptions Used for Pension Benefits Accounting

The discount rate used to determine the current year pension obligation and following year’s pension expense is based on a bond selection-settlement portfolio approach. This approach develops a discount rate by selecting a portfolio of high quality corporate bonds that generate sufficient cash flow to provide for projected benefit payments of the plan. The selected bond portfolio is derived from a universe of non-callable corporate bonds rated Aa quality or higher. After the bond portfolio is selected, a single interest rate is determined that equates the present value of the plan’s projected benefit payments discounted at this rate with the market value of the bonds selected.

The average remaining service period of active covered employees is 11 years for Duke Energy and Duke Energy Progress, 14 years for Progress Energy, 15 years for Duke Energy Florida, eight years for Duke Energy Carolinas, Duke Energy Ohio, and Duke Energy Indiana, and nine years for Piedmont. The following tables present the assumptions used for pension benefit accounting.

	December 31,
	2017					2016		2015
Benefit Obligations
Discount rate				3.60	%	4.10	%	4.40	%
Salary increase	3.50	%	–	4.00	%	4.40	%	4.40	%
Net Periodic Benefit Cost
Discount rate				4.10	%	4.40	%	4.10	%
Salary increase				4.40	%	4.40	%	4.40	%

	Piedmont
	Two Months Ended		Years Ended October 31,
	December 31, 2016		2016		2015
Benefit Obligations
Discount rate	4.10	%	3.80	%	3.85	%
Net Periodic Benefit Cost
Discount rate	3.80	%	3.85	%	3.69	%

Expected Benefit Payments

			Duke				Duke		Duke		Duke		Duke
	Duke		Energy		Progress		Energy		Energy		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
Years ending December 31,
2018	$	23	$	2	$	8	$	3	$	3	$	—	$	—	$	—
2019	21		1		8		2		3		—		—		—
2020	21		1		8		2		3		—		—		—
2021	22		1		8		2		3		—		—		—
2022	25		1		8		2		3		—		—		—
2023-2027	117		6		36		11		15		1		1		2

OTHER POST-RETIREMENT BENEFIT PLANS

Duke Energy provides, and the Subsidiary Registrants participate in, some health care and life insurance benefits for retired employees on a contributory and non-contributory basis. Employees are eligible for these benefits if they have met age and service requirements at retirement, as defined in the plans. The health care benefits include medical, dental and prescription drug coverage and are subject to certain limitations, such as deductibles and copayments.

Duke Energy did not make any pre-funding contributions to its other post-retirement benefit plans during the years ended December 31, 2017, 2016 or 2015.

Components of Net Periodic Other Post-Retirement Benefit Costs

	Year Ended December 31, 2017
				Duke						Duke			Duke			Duke			Duke
	Duke			Energy			Progress			Energy			Energy			Energy			Energy
(in millions)	Energy			Carolinas			Energy			Progress			Florida			Ohio			Indiana			Piedmont
Service cost	$	4		$	1		$	—		$	—		$	—		$	—		$	—		$	1
Interest cost on accumulated post-retirement benefit obligation	34			8			13			7			6			1			3			1
Expected return on plan assets	(14		)	(8		)	—			—			—			—			(1		)	(2		)
Amortization of actuarial loss (gain)	10			(2		)	21			12			9			(2		)	(1		)	1
Amortization of prior service credit	(115		)	(10		)	(84		)	(54		)	(30		)	—			(1		)	—
Curtailment credit (c)	$	(30	)	$	(4	)	$	(16	)	$	—		$	(16	)	$	(2	)	$	(2	)	$	—
Net periodic post-retirement benefit costs(a)(b)	$	(111	)	$	(15	)	$	(66	)	$	(35	)	$	(31	)	$	(3	)	$	(2	)	$	1

	Year Ended December 31, 2016
				Duke						Duke			Duke			Duke			Duke
	Duke			Energy			Progress			Energy			Energy			Energy			Energy
(in millions)	Energy			Carolinas			Energy			Progress			Florida			Ohio			Indiana
Service cost	$	3		$	1		$	1		$	—		$	1		$	—		$	—
Interest cost on accumulated post-retirement benefit obligation	35			8			15			8			7			1			4
Expected return on plan assets	(12		)	(8		)	—			—			—			—			(1		)
Amortization of actuarial loss (gain)	6			(3		)	22			13			9			(2		)	(1		)
Amortization of prior service credit	(141		)	(14		)	(103		)	(68		)	(35		)	—			(1		)
Net periodic post-retirement benefit costs(a)(b)	$	(109	)	$	(16	)	$	(65	)	$	(47	)	$	(18	)	$	(1	)	$	1

	Year Ended December 31, 2015
				Duke						Duke			Duke			Duke			Duke
	Duke			Energy			Progress			Energy			Energy			Energy			Energy
(in millions)	Energy			Carolinas			Energy			Progress			Florida			Ohio			Indiana
Service cost	$	6		$	1		$	1		$	1		$	1		$	—		$	1
Interest cost on accumulated post-retirement benefit obligation	36			9			15			8			7			2			4
Expected return on plan assets	(13		)	(8		)	—			—			—			(1		)	(1		)
Amortization of actuarial loss (gain)	16			(2		)	28			18			10			(2		)	(2		)
Amortization of prior service credit	(140		)	(14		)	(102		)	(68		)	(35		)	—			—
Net periodic post-retirement benefit costs(a)(b)	$	(95	)	$	(14	)	$	(58	)	$	(41	)	$	(17	)	$	(1	)	$	2

(a) Duke Energy amounts exclude $7 million, $8 million and $10 million for the years ended December 2017, 2016 and 2015, respectively, of regulatory asset amortization resulting from purchase accounting adjustments associated with Duke Energy's merger with Cinergy in April 2006.

(b) Duke Energy Ohio amounts exclude $2 million, $2 million and $3 million for the years ended December 2017, 2016 and 2015, respectively, of regulatory asset amortization resulting from purchase accounting adjustments associated with Duke Energy's merger with Cinergy in April 2006.

(c) Curtailment credit resulted from a reduction in average future service of plan participants due to a plan amendment.

	Piedmont
	Years Ended October 31,
(in millions)	2016			2015
Service cost	$	1		$	1
Interest cost on projected benefit obligation	1			2
Expected return on plan assets	(2		)	(2		)
Amortization of actuarial loss	1			—
Net periodic pension costs	$	1		$	1

Amounts Recognized in Accumulated Other Comprehensive Income and Regulatory Assets and Liabilities

	Year Ended December 31, 2017
				Duke					Duke		Duke		Duke			Duke
	Duke			Energy			Progress		Energy		Energy		Energy			Energy
(in millions)	Energy			Carolinas			Energy		Progress		Florida		Ohio			Indiana			Piedmont
Regulatory assets, net increase (decrease)	$	71		$	—		$	81	$	42	$	39	$	—		$	(5	)	$	(11	)
Regulatory liabilities, net increase (decrease)	$	(27	)	$	(2	)	$	—	$	—	$	—	$	(3	)	$	(7	)	$	—
Accumulated other comprehensive (income) loss
Deferred income tax benefit	$	(1	)	$	—		$	—	$	—	$	—	$	—		$	—		$	—
Amortization of prior year prior service credit	3			—			—		—		—		—			—			—
Net amount recognized in accumulated other comprehensive income	$	2		$	—		$	—	$	—	$	—	$	—		$	—		$	—

	Year Ended December 31, 2016
				Duke						Duke			Duke			Duke			Duke
	Duke			Energy			Progress			Energy			Energy			Energy			Energy
(in millions)	Energy			Carolinas			Energy			Progress			Florida			Ohio			Indiana
Regulatory assets, net increase (decrease)	$	53		$	—		$	47		$	38		$	9		$	—		$	(6	)
Regulatory liabilities, net increase (decrease)	$	(114	)	$	(22	)	$	(51	)	$	(25	)	$	(26	)	$	(2	)	$	(12	)
Accumulated other comprehensive (income) loss
Deferred income tax benefit	$	(2	)	$	—		$	—		$	—		$	—		$	—		$	—
Actuarial losses arising during the year	3			—			—			—			—			—			—
Amortization of prior year prior service credit	1			—			1			—			—			—			—
Net amount recognized in accumulated other comprehensive income	$	2		$	—		$	1		$	—		$	—		$	—		$	—

Piedmont's regulatory assets net decreased $1 million for the two months ended December 31, 2016, and increased $2 million and $1 million for the years ended October 31, 2016, and 2015, respectively.

Reconciliation of Funded Status to Accrued Other Post-Retirement Benefit Costs

	Year Ended December 31, 2017
				Duke						Duke			Duke			Duke			Duke
	Duke			Energy			Progress			Energy			Energy			Energy			Energy
(in millions)	Energy			Carolinas			Energy			Progress			Florida			Ohio			Indiana			Piedmont
Change in Projected Benefit Obligation
Accumulated post-retirement benefit obligation at prior measurement date	$	868		$	201		$	357		$	191		$	164		$	32		$	83		$	39
Service cost	4			1			—			—			—			—			—			1
Interest cost	34			8			13			7			6			1			3			1
Plan participants' contributions	17			3			6			3			3			1			2			—
Actuarial (gains) losses	4			(3		)	4			1			3			—			3			1
Transfers	—			2			(1		)	—			(1		)	1			—			—
Plan amendments	(28		)	(5		)	(3		)	(1		)	(2		)	(2		)	(2		)	(9		)
Benefits paid	(86		)	(18		)	(34		)	(17		)	(17		)	(3		)	(11		)	(1		)
Accumulated post-retirement benefit obligation at measurement date	$	813		$	189		$	342		$	184		$	156		$	30		$	78		$	32
Change in Fair Value of Plan Assets
Plan assets at prior measurement date	$	244		$	137		$	1		$	—		$	—		$	7		$	22		$	29
Actual return on plan assets	25			15			1			—			—			2			1			3
Benefits paid	(86		)	(18		)	(34		)	(17		)	(17		)	(3		)	(11		)	(1		)
Employer contributions (reimbursements)	25			(4		)	26			14			14			—			(3		)	—
Plan participants' contributions	17			3			6			3			3			1			2			—
Plan assets at measurement date	$	225		$	133		$	—		$	—		$	—		$	7		$	11		$	31

	Year Ended December 31, 2016
				Duke						Duke			Duke			Duke			Duke
	Duke			Energy			Progress			Energy			Energy			Energy			Energy
(in millions)	Energy			Carolinas			Energy			Progress			Florida			Ohio			Indiana
Change in Projected Benefit Obligation
Accumulated post-retirement benefit obligation at prior measurement date	$	828		$	200		$	354		$	188		$	164		$	35		$	87
Obligation assumed from acquisition	39			—			—			—			—			—			—
Service cost	3			1			1			—			1			—			—
Interest cost	35			8			15			8			7			1			4
Plan participants' contributions	19			3			7			4			3			1			2
Actuarial (gains) losses	33			5			16			8			8			—			3
Transfers	—			1			—			—			—			—			—
Plan amendments	(1		)	—			—			—			—			(1		)	—
Benefits paid	(88		)	(17		)	(36		)	(17		)	(19		)	(4		)	(13		)
Accumulated post-retirement benefit obligation at measurement date	$	868		$	201		$	357		$	191		$	164		$	32		$	83
Change in Fair Value of Plan Assets
Plan assets at prior measurement date	$	208		$	134		$	—		$	—		$	1		$	8		$	19
Assets received from acquisition	29			—			—			—			—			—			—
Actual return on plan assets	14			8			1			—			—			1			2
Benefits paid	(88		)	(17		)	(36		)	(17		)	(19		)	(4		)	(13		)
Employer contributions	62			9			29			13			15			1			12
Plan participants' contributions	19			3			7			4			3			1			2
Plan assets at measurement date	$	244		$	137		$	1		$	—		$	—		$	7		$	22

	Piedmont
	Two Months Ended		Years Ended
(in millions)	December 31, 2016		October 31, 2016
Change in Projected Benefit Obligation
Accumulated post-retirement benefit obligation at prior measurement date	$	39	$	38
Service cost	—		1
Interest cost	—		1
Actuarial gain	—		2
Benefits paid	—		(3		)
Accumulated post-retirement benefit obligation at measurement date	$	39	$	39
Change in Fair Value of Plan Assets
Plan assets at prior measurement date	$	29	$	28
Employer contributions	—		3
Actual return on plan assets	—		1
Benefits paid	—		(3		)
Plan assets at measurement date	$	29	$	29

Amounts Recognized in the Consolidated Balance Sheets

	December 31, 2017
				Duke						Duke			Duke			Duke			Duke
	Duke			Energy			Progress			Energy			Energy			Energy			Energy
(in millions)	Energy			Carolinas			Energy			Progress			Florida			Ohio			Indiana			Piedmont
Current post-retirement liability(a)	$	36		$	—		$	29		$	15		$	14		$	2		$	—		$	—
Noncurrent post-retirement liability(b)	552			56			313			169			142			21			67			1
Total accrued post-retirement liability	$	588		$	56		$	342		$	184		$	156		$	23		$	67		$	1
Regulatory assets	$	125		$	—		$	129		$	80		$	49		$	—		$	46		$	(4	)
Regulatory liabilities	$	147		$	44		$	—		$	—		$	—		$	16		$	64		$	—
Accumulated other comprehensive (income) loss
Deferred income tax expense	$	4		$	—		$	—		$	—		$	—		$	—		$	—		$	—
Prior service credit	(2		)	—			—			—			—			—			—			—
Net actuarial gain	(10		)	—			—			—			—			—			—			—
Net amounts recognized in accumulated other comprehensive income	$	(8	)	$	—		$	—		$	—		$	—		$	—		$	—		$	—
Amounts to be recognized in net periodic pension expense in the next year
Unrecognized net actuarial loss	$	5		$	3		$	1		$	—		$	1		$	—		$	—		$	—
Unrecognized prior service credit	(19		)	(5		)	(7		)	(1		)	(6		)	(1		)	(1		)	(2		)

	December 31, 2016
				Duke						Duke			Duke			Duke			Duke
	Duke			Energy			Progress			Energy			Energy			Energy			Energy
(in millions)	Energy			Carolinas			Energy			Progress			Florida			Ohio			Indiana			Piedmont
Current post-retirement liability(a)	$	38		$	—		$	31		$	17		$	15		$	2		$	—		$	—
Noncurrent post-retirement liability(b)	586			64			325			174			149			23			63			10
Total accrued post-retirement liability	$	624		$	64		$	356		$	191		$	164		$	25		$	63		$	10
Regulatory assets	$	54		$	—		$	48		$	38		$	10		$	—		$	51		$	7
Regulatory liabilities	$	174		$	46		$	—		$	—		$	—		$	19		$	71		$	—
Accumulated other comprehensive (income) loss
Deferred income tax expense	$	5		$	—		$	—		$	—		$	—		$	—		$	—		$	—
Prior service credit	(5		)	—			—			—			—			—			—			—
Net actuarial gain	(10		)	—			—			—			—			—			—			—
Net amounts recognized in accumulated other comprehensive income	$	(10	)	$	—		$	—		$	—		$	—		$	—		$	—		$	—
Amounts to be recognized in net periodic pension expense in the next year
Unrecognized net actuarial loss (gain)	$	10		$	(2	)	$	21		$	12		$	9		$	(2	)	$	(6	)	$	—
Unrecognized prior service credit	(115		)	(10		)	(85		)	(55		)	(30		)	—			(1		)	—

(a) Included in Other within Current Liabilities on the Consolidated Balance Sheets. 

(b) Included in Accrued pension and other post-retirement benefit costs on the Consolidated Balance Sheets.

Assumptions Used for Other Post-Retirement Benefits Accounting

The discount rate used to determine the current year other post-retirement benefits obligation and following year’s other post-retirement benefits expense is based on a bond selection-settlement portfolio approach. This approach develops a discount rate by selecting a portfolio of high quality corporate bonds that generate sufficient cash flow to provide for projected benefit payments of the plan. The selected bond portfolio is derived from a universe of non-callable corporate bonds rated Aa quality or higher. After the bond portfolio is selected, a single interest rate is determined that equates the present value of the plan’s projected benefit payments discounted at this rate with the market value of the bonds selected. The average remaining service period of active covered employees is nine years for Duke Energy, eight years for Duke Energy Carolinas, seven years for Duke Energy Florida, Duke Energy Ohio, and Piedmont, and six years for Progress Energy, Duke Energy Progress, and Duke Energy Indiana.

The following tables present the assumptions used for other post-retirement benefits accounting.

	December 31,
	2017		2016		2015
Benefit Obligations
Discount rate	3.60	%	4.10	%	4.40	%
Net Periodic Benefit Cost
Discount rate	4.10	%	4.40	%	4.10	%
Expected long-term rate of return on plan assets	6.50	%	6.50	%	6.50	%
Assumed tax rate	35	%	35	%	35	%

	Piedmont
	Two Months Ended		Years Ended October 31,
	December 31, 2016		2016		2015
Benefit Obligations
Discount rate	4.10	%	3.80	%	4.38	%
Net Periodic Benefit Cost
Discount rate	3.80	%	4.38	%	4.03	%
Expected long-term rate of return on plan assets	6.75	%	7.25	%	7.50	%

Assumed Health Care Cost Trend Rate

	December 31,
	2017		2016
Health care cost trend rate assumed for next year	7.00	%	7.00	%
Rate to which the cost trend is assumed to decline (the ultimate trend rate)	4.75	%	4.75	%
Year that rate reaches ultimate trend	2024		2023

Sensitivity to Changes in Assumed Health Care Cost Trend Rates

	Year Ended December 31, 2017
				Duke						Duke			Duke			Duke			Duke
	Duke			Energy			Progress			Energy			Energy			Energy			Energy
(in millions)	Energy			Carolinas			Energy			Progress			Florida			Ohio			Indiana			Piedmont
1-Percentage Point Increase
Effect on total service and interest costs	$	1		$	—		$	1		$	1		$	—		$	—		$	—		$	—
Effect on post-retirement benefit obligation	27			6			11			6			5			1			3			1
1-Percentage Point Decrease
Effect on total service and interest costs	(1		)	—			—			—			—			—			—			—
Effect on post-retirement benefit obligation	(24		)	(6		)	(10		)	(5		)	(5		)	(1		)	(2		)	(1		)

Expected Benefit Payments

			Duke				Duke		Duke		Duke		Duke
	Duke		Energy		Progress		Energy		Energy		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
Years ending December 31,
2018	$	78	$	17	$	30	$	16	$	14	$	3	$	9	$	2
2019	76		17		29		15		14		3		9		2
2020	73		17		29		15		14		3		8		2
2021	71		17		28		15		13		3		7		3
2022	68		17		27		14		13		3		7		3
2023 – 2027	290		70		117		63		54		12		29		13

PLAN ASSETS

Description and Allocations

Duke Energy Master Retirement Trust

Assets for both the qualified pension and other post-retirement benefits are maintained in the Duke Energy Master Retirement Trust. Qualified pension and other post-retirement assets related to Piedmont were transferred into the Duke Energy Master Retirement Trust during 2017. Approximately 98 percent of the Duke Energy Master Retirement Trust assets were allocated to qualified pension plans and approximately 2 percent were allocated to other post-retirement plans (comprised of 401(h) accounts), as of December 31, 2017, and 2016. The investment objective of the Duke Energy Master Retirement Trust is to achieve reasonable returns, subject to a prudent level of portfolio risk, for the purpose of enhancing the security of benefits for plan participants.

As of December 31, 2017, Duke Energy assumes pension and other post-retirement plan assets will generate a long-term rate of return of 6.50 percent. The expected long-term rate of return was developed using a weighted average calculation of expected returns based primarily on future expected returns across asset classes considering the use of active asset managers, where applicable. The asset allocation targets were set after considering the investment objective and the risk profile. Equity securities are held for their higher expected returns. Debt securities are primarily held to hedge the qualified pension plan liability. Hedge funds, real estate and other global securities are held for diversification. Investments within asset classes are diversified to achieve broad market participation and reduce the impact of individual managers or investments.

In 2013, Duke Energy adopted a de-risking investment strategy for the Duke Energy Master Retirement Trust. As the funded status of the pension plans increase, the targeted allocation to fixed-income assets may be increased to better manage Duke Energy’s pension liability and reduce funded status volatility. Duke Energy regularly reviews its actual asset allocation and periodically rebalances its investments to the targeted allocation when considered appropriate.

The Duke Energy Master Retirement Trust is authorized to engage in the lending of certain plan assets. Securities lending is an investment management enhancement that utilizes certain existing securities of the Duke Energy Master Retirement Trust to earn additional income. Securities lending involves the loaning of securities to approved parties. In return for the loaned securities, the Duke Energy Master Retirement Trust receives collateral in the form of cash and securities as a safeguard against possible default of any borrower on the return of the loan under terms that permit the Duke Energy Master Retirement Trust to sell the securities. The Duke Energy Master Retirement Trust mitigates credit risk associated with securities lending arrangements by monitoring the fair value of the securities loaned, with additional collateral obtained or refunded as necessary. The fair value of securities on loan was approximately $195 million and $156 million at December 31, 2017, and 2016, respectively. Cash and securities obtained as collateral exceeded the fair value of the securities loaned at December 31, 2017, and 2016, respectively. Securities lending income earned by the Duke Energy Master Retirement Trust was immaterial for the years ended December 31, 2017, 2016 and 2015, respectively.

Qualified pension and other post-retirement benefits for the Subsidiary Registrants are derived from the Duke Energy Master Retirement Trust, as such, each are allocated their proportionate share of the assets discussed below.

The following table includes the target asset allocations by asset class at December 31, 2017, and the actual asset allocations for the Duke Energy Master Retirement Trust.

			Actual Allocation at
	Target		December 31,
	Allocation		2017		2016(a)
U.S. equity securities	10	%	11	%	11	%
Non-U.S. equity securities	8	%	8	%	8	%
Global equity securities	10	%	10	%	10	%
Global private equity securities	3	%	2	%	2	%
Debt securities	63	%	63	%	63	%
Hedge funds	2	%	2	%	2	%
Real estate and cash	2	%	2	%	2	%
Other global securities	2	%	2	%	2	%
Total	100	%	100	%	100	%

(a) Excludes Piedmont Pension Assets, which had a targeted asset allocation of 60 percent return-seeking and 40 percent liability hedging fixed-income. Actual asset allocations were 61 percent return-seeking and 39 percent liability hedging fixed-income at December 31, 2016.

Other post-retirement assets

Duke Energy's other post-retirement assets are comprised of Voluntary Employees' Beneficiary Association (VEBA) trusts and 401(h) accounts held within the Duke Energy Master Retirement Trust. Duke Energy's investment objective is to achieve sufficient returns, subject to a prudent level of portfolio risk, for the purpose of promoting the security of plan benefits for participants.  

The following table presents target and actual asset allocations for the VEBA trusts at December 31, 2017.

			Actual Allocation at
	Target		December 31,
	Allocation		2017		2016
U.S. equity securities	32	%	41	%	39	%
Non-US equity securities	6	%	8	%	—	%
Real estate	2	%	2	%	2	%
Debt securities	45	%	36	%	37	%
Cash	15	%	13	%	22	%
Total	100	%	100	%	100	%

Fair Value Measurements

Duke Energy classifies recurring and non-recurring fair value measurements based on the fair value hierarchy as discussed in Note 16.

Valuation methods of the primary fair value measurements disclosed below are as follows:

Investments in equity securities

Investments in equity securities are typically valued at the closing price in the principal active market as of the last business day of the reporting period. Principal active markets for equity prices include published exchanges such as NASDAQ and NYSE. Foreign equity prices are translated from their trading currency using the currency exchange rate in effect at the close of the principal active market. Prices have not been adjusted to reflect after-hours market activity. The majority of investments in equity securities are valued using Level 1 measurements. When the price of an institutional commingled fund is unpublished, it is not categorized in the fair value hierarchy, even though the funds are readily available at the fair value.

Investments in corporate debt securities and U.S. government securities

Most debt investments are valued based on a calculation using interest rate curves and credit spreads applied to the terms of the debt instrument (maturity and coupon interest rate) and consider the counterparty credit rating. Most debt valuations are Level 2 measurements. If the market for a particular fixed-income security is relatively inactive or illiquid, the measurement is Level 3. U.S. Treasury debt is typically Level 2.

Investments in short-term investment funds

Investments in short-term investment funds are valued at the net asset value of units held at year end and are readily redeemable at the measurement date. Investments in short-term investment funds with published prices are valued as Level 1. Investments in short-term investment funds with unpublished prices are valued as Level 2.

Investments in real estate limited partnerships

Investments in real estate limited partnerships are valued by the trustee at each valuation date (monthly). As part of the trustee’s valuation process, properties are externally appraised generally on an annual basis, conducted by reputable, independent appraisal firms, and signed by appraisers that are members of the Appraisal Institute, with the professional designation MAI. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. There are three valuation techniques that can be used to value investments in real estate assets: the market, income or cost approach. The appropriateness of each valuation technique depends on the type of asset or business being valued. In addition, the trustee may cause additional appraisals to be performed as warranted by specific asset or market conditions. Property valuations and the salient valuation-sensitive assumptions of each direct investment property are reviewed by the trustee quarterly and values are adjusted if there has been a significant change in circumstances related to the investment property since the last valuation. Value adjustments for interim capital expenditures are only recognized to the extent that the valuation process acknowledges a corresponding increase in fair value. An independent firm is hired to review and approve quarterly direct real estate valuations. Key inputs and assumptions used to determine fair value includes among others, rental revenue and expense amounts and related revenue and expense growth rates, terminal capitalization rates and discount rates. Development investments are valued using cost incurred to date as a primary input until substantive progress is achieved in terms of mitigating construction and leasing risk at which point a discounted cash flow approach is more heavily weighted. Key inputs and assumptions in addition to those noted above used to determine the fair value of development investments include construction costs and the status of construction completion and leasing. Investments in real estate limited partnerships are valued at net asset value of units held at year end and are not readily redeemable at the measurement date. Investments in real estate limited partnerships are not categorized within the fair value hierarchy.

Duke Energy Master Retirement Trust

The following tables provide the fair value measurement amounts for the Duke Energy Master Retirement Trust qualified pension and other post-retirement assets.

	December 31, 2017
	Total Fair								Not
(in millions)	Value		Level 1		Level 2		Level 3		Categorized(b)
Equity securities	$	2,823	$	1,976	$	—	$	—	847
Corporate debt securities	4,694		—		4,694		—		—
Short-term investment funds	246		192		54		—		—
Partnership interests	137		—		—		—		137
Hedge funds	226		—		—		—		226
Real estate limited partnerships	135		—		—		—		135
U.S. government securities	762		—		762		—		—
Guaranteed investment contracts	28		—		—		28		—
Governments bonds – foreign	38		—		38		—		—
Cash	6		6		—		—		—
Government and commercial mortgage backed securities	2		—		2		—		—
Net pending transactions and other investments	17		15		2		—		—
Total assets(a)	$	9,114	$	2,189	$	5,552	$	28	$	1,345

(a) Duke Energy Carolinas, Progress Energy, Duke Energy Progress, Duke Energy Florida, Duke Energy Ohio, Duke Energy Indiana, and Piedmont were allocated approximately 27 percent, 30 percent, 15 percent, 15 percent, 5 percent, 8 percent, and 4 percent, respectively, of the Duke Energy Master Retirement Trust at December 31, 2017. Accordingly, all amounts included in the table above are allocable to the Subsidiary Registrants using these percentages.

(b) Certain investments that are measured at fair value using the net asset value per share practical expedient have not been categorized in the fair value hierarchy.

	December 31, 2016
	Total Fair								Not
(in millions)	Value		Level 1		Level 2		Level 3		Categorized(b)
Equity securities	$	2,472	$	1,677	$	27	$	9	759
Corporate debt securities	4,330		8		4,322		—		—
Short-term investment funds	476		211		265		—		—
Partnership interests	157		—		—		—		157
Hedge funds	232		—		—		—		232
Real estate limited partnerships	144		17		—		—		127
U.S. government securities	734		—		734		—		—
Guaranteed investment contracts	29		—		—		29		—
Governments bonds – foreign	32		—		32		—		—
Cash	17		15		2		—		—
Net pending transactions and other investments	32		1		6		—		25
Total assets(a)	$	8,655	$	1,929	$	5,388	$	38	$	1,300

(a) Duke Energy Carolinas, Progress Energy, Duke Energy Progress, Duke Energy Florida, Duke Energy Ohio and Duke Energy Indiana were allocated approximately 27 percent, 30 percent, 15 percent, 15 percent, 5 percent and 8 percent, respectively, of the Duke Energy Master Retirement Trust and Piedmont's Pension assets at December 31, 2016. Accordingly, all amounts included in the table above are allocable to the Subsidiary Registrants using these percentages.

(b) Certain investments that are measured at fair value using the net asset value per share practical expedient have not been categorized in the fair value hierarchy.

The following table provides a reconciliation of beginning and ending balances of Duke Energy Master Retirement Trust qualified pension and other post-retirement assets and Piedmont Pension Assets at fair value on a recurring basis where the determination of fair value includes significant unobservable inputs (Level 3).

(in millions)	2017			2016
Balance at January 1	$	38		$	31
Combination of Piedmont Pension Assets	—			9
Sales	(2		)	(2		)
Total gains (losses) and other, net	1			—
Transfer of Level 3 assets to other classifications	(9		)	—
Balance at December 31	$	28		$	38

Other post-retirement assets

The following tables provide the fair value measurement amounts for VEBA trust assets.

	December 31, 2017
	Total Fair
(in millions)	Value		Level 2
Cash and cash equivalents	$	8	$	8
Real estate	1		1
Equity securities	28		28
Debt securities	21		21
Total assets	$	58	$	58

	December 31, 2016
	Total Fair
(in millions)	Value		Level 2
Cash and cash equivalents	$	14	$	14
Real estate	1		1
Equity securities	26		26
Debt securities	25		25
Total assets	$	66	$	66

EMPLOYEE SAVINGS PLANS

Retirement Savings Plan

Duke Energy or its affiliates sponsor, and the Subsidiary Registrants participate in, employee savings plans that cover substantially all U.S. employees. Most employees participate in a matching contribution formula where Duke Energy provides a matching contribution generally equal to 100 percent of employee before-tax and Roth 401(k) contributions of up to 6 percent of eligible pay per pay period (5 percent for Piedmont employees). Dividends on Duke Energy shares held by the savings plans are charged to retained earnings when declared and shares held in the plans are considered outstanding in the calculation of basic and diluted EPS.

As of January 1, 2014, for new and rehired non-union and certain unionized employees (excludes Piedmont employees until 2018 plan year, discussed below) who are not eligible to participate in Duke Energy’s defined benefit plans, an additional employer contribution of 4 percent of eligible pay per pay period, which is subject to a three-year vesting schedule, is provided to the employee’s savings plan account.

The following table includes pretax employer matching contributions made by Duke Energy and expensed by the Subsidiary Registrants.

			Duke				Duke		Duke		Duke		Duke
	Duke		Energy		Progress		Energy		Energy		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont(a)
Years ended December 31,
2017	$	179	$	61	$	53	$	37	$	16	$	3	$	9	$	7
2016	169		57		50		35		15		3		8		—
2015	159		54		48		34		13		3		7		—

(a) Piedmont's pretax employer matching contributions were $1 million, $7 million and $7 million during the two months ended December 31, 2016 and for the years ended October 31, 2016 and 2015, respectively.

Money Purchase Pension Plan

Piedmont sponsors the MPP plan, which is a defined contribution pension plan that allows employees to direct investments and assume risk of investment returns. Under the MPP plan, Piedmont annually deposits a percentage of each participant’s pay into an account of the MPP plan. This contribution equals 4 percent of the participant’s eligible compensation plus an additional 4 percent of eligible compensation above the Social Security wage base up to the IRS compensation limit. The participant is vested in MPP plan after three years of service. No contributions were made to the MPP plan during the two months ended December 31, 2016. Piedmont contributed $2 million to the MPP plan during each of the years ended December 31, 2017, October 31, 2016 and 2015. Effective December 31, 2017, the MPP Plan was merged into the Retirement Savings Plan and the money purchase plan formula was discontinued. Beginning with the 2018 plan year, the former MPP Plan participants are eligible to receive the additional employer contribution under the Retirement Savings Plan, discussed above.