Retirement and Postemployment Benefits (Tables)

12 Months Ended

Dec. 31, 2017

Defined Benefit Plan Disclosure [Line Items]

Schedule Of Net Periodic Defined Benefit Costs (Credits)

The following table provides the components of net periodic defined benefit costs for PPL's domestic (U.S.) and WPD's (U.K.) pension and other postretirement benefit plans for the years ended December 31.

	Pension Benefits
	U.S.									U.K.									Other Postretirement Benefits
	2017			2016			2015			2017			2016			2015			2017			2016			2015
Net periodic defined benefit costs (credits):
Service cost	$	65		$	66		$	96		$	76		$	69		$	79		$	7		$	7		$	11
Interest cost	168			174			194			178			235			314			23			26			26
Expected return on plan assets	(231		)	(228		)	(258		)	(514		)	(504		)	(523		)	(22		)	(22		)	(26		)
Amortization of:
Prior service cost (credit)	10			8			7			—			—			—			(1		)	—			1
Actuarial (gain) loss	69			50			84			144			138			158			1			1			—
Net periodic defined benefit costs (credits) prior to settlements and termination benefits	81			70			123			(116		)	(62		)	28			8			12			12
Settlements	1			3			—			—			—			—			—			—			—
Termination benefits	1			—			—			—			—			—			—			—			—
Net periodic defined benefit costs (credits)	$	83		$	73		$	123		$	(116	)	$	(62	)	$	28		$	8		$	12		$	12

	Pension Benefits
	U.S.									U.K.									Other Postretirement Benefits
	2017			2016			2015			2017			2016			2015			2017			2016			2015
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross:
Divestiture (a)	$	—		$	—		$	(353	)	$	—		$	—		$	—		$	—		$	—		$	(6	)
Settlement	(1		)	(3		)	—			—			—			—			—			—			—
Net (gain) loss	27			253			63			346			7			508			(28		)	9			(9		)
Prior service cost (credit)	(1		)	15			18			—			—			—			8			—			—
Amortization of:
Prior service (cost) credit	(10		)	(8		)	(7		)	—			—			—			1			(1		)	(1		)
Actuarial gain (loss)	(69		)	(50		)	(85		)	(144		)	(138		)	(158		)	(1		)	(1		)	—
Total recognized in OCI and regulatory assets/liabilities (b)	(54		)	207			(364		)	202			(131		)	350			(20		)	7			(16		)
Total recognized in net periodic defined benefit costs, OCI and regulatory assets/liabilities (b)	$	29		$	280		$	(241	)	$	86		$	(193	)	$	378		$	(12	)	$	19		$	(4	)

(a) As a result of the spinoff of PPL Energy Supply, amounts in AOCI were allocated to certain former active and inactive employees of PPL Energy Supply and included in the distribution. See Note 8 for additional details.

(b) WPD is not subject to accounting for the effects of certain types of regulation as prescribed by GAAP. As a result, WPD does not record regulatory assets/liabilities.

Schedule of Amounts Recognized in Other Comprehensive Income and Regulatory Assets and Liabilities

For PPL's U.S. pension benefits and for other postretirement benefits, the amounts recognized in OCI and regulatory assets/liabilities for the years ended December 31 were as follows:

	U.S. Pension Benefits									Other Postretirement Benefits
	2017			2016			2015			2017			2016		2015
OCI	$	(53	)	$	236		$	(269	)	$	(25	)	$	7	$	12
Regulatory assets/liabilities	(1		)	(29		)	(95		)	5			—		(28		)
Total recognized in OCI and regulatory assets/liabilities	$	(54	)	$	207		$	(364	)	$	(20	)	$	7	$	(16	)

Schedule of Amounts to be Amortized from AOCI and Regulatory Assets/Liabilities in Next Fiscal Year

The estimated amounts to be amortized from AOCI and regulatory assets/liabilities into net periodic defined benefit costs in 2018 are as follows:

	Pension Benefits
	U.S.		U.K.
Prior service cost (credit)	$	10	$	—
Actuarial (gain) loss	86		152
Total	$	96	$	152
Amortization from Balance Sheet:
AOCI	$	28	$	152
Regulatory assets/liabilities	68		—
Total	$	96	$	152

Schedule of Net Periodic Defined Benefit Costs Included in Income Statement

The following net periodic defined benefit costs (credits) were charged to operating expense or regulatory assets, excluding amounts charged to construction and other non-expense accounts. The U.K. pension benefits apply to PPL only.

	Pension Benefits
	U.S.						U.K.									Other Postretirement Benefits
	2017		2016		2015		2017			2016			2015			2017		2016		2015
PPL	$	59	$	53	$	71	$	(151	)	$	(95	)	$	(21	)	$	5	$	7	$	8
PPL Electric (a)	12		10		15											—		1		—
LKE (b)	28		24		37											5		6		8
LG&E (b)	8		8		12											3		3		4
KU (a) (b)	4		5		9											1		2		2

(a) PPL Electric and KU do not directly sponsor any defined benefit plans. PPL Electric and KU were allocated these costs of defined benefit plans sponsored by PPL Services (for PPL Electric) and by LKE (for KU), based on their participation in those plans, which management believes are reasonable. KU is also allocated costs of defined benefit plans from LKS for defined benefit plans sponsored by LKE. See Note 14 for additional information on costs allocated to KU from LKS.

(b) As a result of the 2014 Kentucky rate case settlement that became effective July 1, 2015, the difference between net periodic defined benefit costs calculated in accordance with LKE's, LG&E's and KU's pension accounting policy and the net periodic defined benefit costs calculated using a 15 year amortization period for gains and losses is recorded as a regulatory asset. Of the costs charged to operating expense or regulatory assets, excluding amounts charged to construction and other non-expense accounts, $4 million for LG&E and $2 million for KU were recorded as regulatory assets in 2017, $3 million for LG&E and $2 million for KU were recorded as regulatory assets in 2016 and $4 million for LG&E and $1 million for KU were recorded as regulatory assets in 2015.

Defined Benefit Plan Assumptions and Impact of One Point Change on Postretirement Plans

The following weighted-average assumptions were used in the valuation of the benefit obligations at December 31. The U.K. pension benefits apply to PPL only.

	Pension Benefits
	U.S.				U.K.				Other Postretirement Benefits
	2017		2016		2017		2016		2017		2016
PPL
Discount rate	3.70	%	4.21	%	2.65	%	2.87	%	3.64	%	4.11	%
Rate of compensation increase	3.78	%	3.95	%	3.50	%	3.50	%	3.75	%	3.92	%
LKE
Discount rate	3.69	%	4.19	%					3.65	%	4.12	%
Rate of compensation increase	3.50	%	3.50	%					3.50	%	3.50	%
LG&E
Discount rate	3.65	%	4.13	%

The following weighted-average assumptions were used to determine the net periodic defined benefit costs for the years ended December 31. The U.K. pension benefits apply to PPL only.

	Pension Benefits
	U.S.						U.K.						Other Postretirement Benefits
	2017		2016		2015		2017		2016		2015		2017		2016		2015
PPL
Discount rate service cost (b)	4.21	%	4.59	%	4.25	%	2.99	%	3.90	%	3.85	%	4.11	%	4.48	%	4.09	%
Discount rate interest cost (b)	4.21	%	4.59	%	4.25	%	2.41	%	3.14	%	3.85	%	4.11	%	4.48	%	4.09	%
Rate of compensation increase	3.95	%	3.93	%	3.91	%	3.50	%	4.00	%	4.00	%	3.92	%	3.91	%	3.86	%
Expected return on plan assets (a)	7.00	%	7.00	%	7.00	%	7.22	%	7.20	%	7.19	%	6.21	%	6.11	%	6.06	%
LKE
Discount rate	4.19	%	4.56	%	4.25	%							4.12	%	4.49	%	4.06	%
Rate of compensation increase	3.50	%	3.50	%	3.50	%							3.50	%	3.50	%	3.50	%
Expected return on plan assets (a)	7.00	%	7.00	%	7.00	%							6.82	%	6.82	%	6.82	%

	Pension Benefits
	U.S.						U.K.			Other Postretirement Benefits
	2017		2016		2015		2017	2016	2015	2017	2016	2015
LG&E
Discount rate	4.13	%	4.49	%	4.20	%
Expected return on plan assets (a)	7.00	%	7.00	%	7.00	%

(a) The expected long-term rates of return for pension and other postretirement benefits are based on management's projections using a best-estimate of expected returns, volatilities and correlations for each asset class. Each plan's specific current and expected asset allocations are also considered in developing a reasonable return assumption.

(b) As of January 1, 2016, WPD began using individual spot rates from the yield curve used to discount the benefit obligation to measure service cost and interest cost. PPL's U.S. plans use a single discount rate derived from an individual bond matching model to measure the benefit obligation, service cost and interest cost. See Note 1 for additional details.

(PPL and LKE)

The following table provides the assumed health care cost trend rates for the years ended December 31:

	2017		2016		2015
PPL and LKE
Health care cost trend rate assumed for next year
– obligations	6.6	%	7.0	%	6.8	%
– cost	7.0	%	6.8	%	7.2	%
Rate to which the cost trend rate is assumed to decline (the ultimate trend rate)
– obligations	5.0	%	5.0	%	5.0	%
– cost	5.0	%	5.0	%	5.0	%
Year that the rate reaches the ultimate trend rate
– obligations	2022		2022		2020
– cost	2022		2020		2020

A one percentage point change in the assumed health care costs trend rate assumption would have had the following effects on the other postretirement benefit plans in 2017:

	One Percentage Point
	Increase		Decrease
Effect on accumulated postretirement benefit obligation
PPL	$	4	$	(4	)
LKE	3		(3		)

Schedule of Funded Status of Defined Benefit Plans

The funded status of PPL's plans at December 31 was as follows:

	Pension Benefits
	U.S.						U.K.						Other Postretirement Benefits
	2017			2016			2017			2016			2017			2016
Change in Benefit Obligation
Benefit Obligation, beginning of period	$	4,079		$	3,863		$	7,383		$	8,404		$	591		$	596
Service cost	65			66			76			69			7			7
Interest cost	168			174			178			235			23			26
Participant contributions	—			—			13			14			14			14
Plan amendments	(1		)	14			—			—			8			—
Actuarial (gain) loss	233			214			293			484			4			11
Settlements	(6		)	(9		)	(1		)	—			—			—
Termination benefits	1			—			—			—			—			—
Gross benefits paid	(251		)	(243		)	(345		)	(357		)	(59		)	(64		)
Federal subsidy	—			—			—			—			1			1
Currency conversion	—			—			622			(1,466		)	—			—
Benefit Obligation, end of period	4,288			4,079			8,219			7,383			589			591
Change in Plan Assets
Plan assets at fair value, beginning of period	3,243			3,227			7,211			7,625			378			379
Actual return on plan assets	437			189			480			979			54			25
Employer contributions	65			79			486			330			15			19
Participant contributions	—			—			13			14			13			14
Settlements	(6		)	(9		)	(1		)	—			—			—
Gross benefits paid	(251		)	(243		)	(345		)	(357		)	(55		)	(59		)
Currency conversion	—			—			646			(1,380		)	—			—
Plan assets at fair value, end of period	3,488			3,243			8,490			7,211			405			378
Funded Status, end of period	$	(800	)	$	(836	)	$	271		$	(172	)	$	(184	)	$	(213	)
Amounts recognized in the Balance Sheets consist of:
Noncurrent asset	$	—		$	—		$	284		$	10		$	2		$	2
Current liability	(13		)	(17		)	—			—			(3		)	(3		)
Noncurrent liability	(787		)	(819		)	(13		)	(182		)	(183		)	(212		)
Net amount recognized, end of period	$	(800	)	$	(836	)	$	271		$	(172	)	$	(184	)	$	(213	)
Amounts recognized in AOCI and regulatory assets/liabilities (pre-tax) consist of:
Prior service cost (credit)	$	49		$	59		$	—		$	—		$	9		$	—
Net actuarial (gain) loss	1,134			1,178			2,755			2,553			16			45
Total (a)	$	1,183		$	1,237		$	2,755		$	2,553		$	25		$	45
Total accumulated benefit obligation for defined benefit pension plans	$	4,000		$	3,807		$	7,542		$	6,780

(a) WPD is not subject to accounting for the effects of certain types of regulation as prescribed by GAAP and as a result, does not record regulatory assets/liabilities.

For PPL's U.S. pension and other postretirement benefit plans, the amounts recognized in AOCI and regulatory assets/liabilities at December 31 were as follows:

	U.S. Pension Benefits				Other Postretirement Benefits
	2017		2016		2017		2016
AOCI	$	374	$	357	$	15	$	20
Regulatory assets/liabilities	809		880		10		25
Total	$	1,183	$	1,237	$	25	$	45

Schedule of Projected or Accumulated Benefit Obligations In Excess of Plan Assets

The following tables provide information on pension plans where the projected benefit obligation (PBO) or accumulated benefit obligation (ABO) exceed the fair value of plan assets:

	U.S.				U.K.
	PBO in excess of plan assets				PBO in excess of plan assets
	2017		2016		2017		2016
Projected benefit obligation	$	4,288	$	4,079	$	3,083	$	3,403
Fair value of plan assets	3,488		3,243		3,070		3,221
	U.S.				U.K.
	ABO in excess of plan assets				ABO in excess of plan assets
	2017		2016		2017		2016
Accumulated benefit obligation	$	4,000	$	3,807	$	10	$	657
Fair value of plan assets	3,488		3,243		—		643

Schedules of Asset Allocation of U.S. Pension Trusts Assets

The asset allocation for the trust and the target allocation by portfolio at December 31 are as follows:

	Percentage of trust assets				2017
	2017 (a)		2016		Target Asset Allocation (a)
Growth Portfolio	56	%	52	%	55	%
Equity securities	32	%	30	%
Debt securities (b)	14	%	12	%
Alternative investments	10	%	10	%
Immunizing Portfolio	43	%	46	%	43	%
Debt securities (b)	39	%	43	%
Derivatives	4	%	3	%
Liquidity Portfolio	1	%	2	%	2	%
Total	100	%	100	%	100	%

(a) Allocations exclude consideration of a group annuity contract held by the LG&E and KU Retirement Plan.

(b) Includes commingled debt funds, which PPL treats as debt securities for asset allocation purposes.

Schedule of Fair Value of Financial Assets for U.S. Pension Plan Assets

The fair value of net assets in the Master Trust by asset class and level within the fair value hierarchy was:

	December 31, 2017								December 31, 2016
			Fair Value Measurements Using								Fair Value Measurements Using
	Total		Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3
PPL Services Corporation Master Trust
Cash and cash equivalents	$	301	$	301	$	—	$	—	$	181	$	181	$	—	$	—
Equity securities:
U.S. Equity	229		229		—		—		152		152		—		—
U.S. Equity fund measured at NAV (a)	364		—		—		—		272		—		—		—
International equity fund at NAV (a)	538		—		—		—		551		—		—		—
Commingled debt measured at NAV (a)	611		—		—		—		546		—		—		—

	December 31, 2017									December 31, 2016
				Fair Value Measurements Using									Fair Value Measurements Using
	Total			Level 1		Level 2		Level 3		Total			Level 1		Level 2		Level 3
Debt securities:
U.S. Treasury and U.S. government sponsored agency	186			186		—		—		381			381		—		—
Corporate	883			—		870		13		850			—		837		13
Other	10			—		10		—		8			—		8		—
Alternative investments:
Real estate measured at NAV (a)	109			—		—		—		102			—		—		—
Private equity measured at NAV (a)	80			—		—		—		80			—		—		—
Hedge funds measured at NAV (a)	175			—		—		—		167			—		—		—
Derivatives:
Interest rate swaps and swaptions	50			—		50		—		61			—		61		—
Other	1			—		1		—		3			—		3		—
Insurance contracts	24			—		—		24		27			—		—		27
PPL Services Corporation Master Trust assets, at fair value	3,561			$	716	$	931	$	37	3,381			$	714	$	909	$	40
Receivables and payables, net (b)	72									(15		)
401(h) accounts restricted for other postretirement benefit obligations	(145		)							(123		)
Total PPL Services Corporation Master Trust pension assets	$	3,488								$	3,243

(a) In accordance with accounting guidance certain investments that are measured at fair value using the net asset value per share (NAV), or its equivalent, practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in the table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the statement of financial position.

(b) Receivables and payables represent amounts for investments sold/purchased but not yet settled along with interest and dividends earned but not yet received.

Reconciliation of U.S. Pension Trust Assets Classified as Level 3 Included in Earnings

A reconciliation of the Master Trust assets classified as Level 3 at December 31, 2017 is as follows:

	Corporate debt		Insurance contracts			Total
Balance at beginning of period	$	13	$	27		$	40
Actual return on plan assets
Relating to assets still held at the reporting date	—		1			1
Purchases, sales and settlements	—		(4		)	(4		)
Balance at end of period	$	13	$	24		$	37

A reconciliation of the Master Trust assets classified as Level 3 at December 31, 2016 is as follows: 

	Corporate debt		Insurance contracts			Total
Balance at beginning of period	$	10	$	32		$	42
Actual return on plan assets
Relating to assets still held at the reporting date	—		1			1
Purchases, sales and settlements	3		(6		)	(3		)
Balance at end of period	$	13	$	27		$	40

Schedules of Target Allocation of U.S. Other Postretirement Benefit Plans VEBA Trust

The asset allocation for the PPL VEBA trusts, excluding LKE, and the target allocation, by asset class, at December 31 are detailed below.

	Percentage of plan assets				Target Asset Allocation
	2017		2016		2017
Asset Class
U.S. Equity securities	47	%	48	%	45	%
Debt securities (a)	49	%	50	%	50	%
Cash and cash equivalents (b)	4	%	2	%	5	%
Total	100	%	100	%	100	%

(a) Includes commingled debt funds and debt securities.

(b) Includes money market funds.

Schedule of Fair Value of Financial Assets for U.S. Postretirement Benefits

The fair value of assets in the U.S. other postretirement benefit plans by asset class and level within the fair value hierarchy was:

	December 31, 2017								December 31, 2016
			Fair Value Measurement Using								Fair Value Measurement Using
	Total		Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3
Money market funds	$	10	$	10	$	—	$	—	$	5	$	5	$	—	$	—
U.S. Equity securities:
Large-cap equity fund measure at NAV (a)	123		—		—		—		123		—		—		—
Commingled debt fund measured at NAV (a)	96		—		—		—		114		—		—		—
Debt securities:
Corporate bonds	30		—		30		—		—		—		—		—
Municipalities	—		—		—		—		12		—		12		—
Total VEBA trust assets, at fair value	259		$	10	$	30	$	—	254		$	5	$	12	$	—
Receivables and payables, net (b)	1								1
401(h) account assets	145								123
Total other postretirement benefit plan assets	$	405							$	378

(a) In accordance with accounting guidance certain investments that are measured at fair value using the net asset value per share (NAV), or its equivalent, practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in the table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the statement of financial position.

(b) Receivables and payables represent amounts for investments sold/purchased but not yet settled along with interest and dividends earned but not yet received.

Schedules of Asset Allocation of U.K. Pension Plan Assets

The asset allocation and target allocation at December 31 of WPD's pension plans are detailed below.

					Target Asset
	Percentage of plan assets				Allocation
	2017		2016		2017
Asset Class
Cash and cash equivalents	2	%	1	%	—	%
Equity securities
U.K.	2	%	3	%	2	%
European (excluding the U.K.)	1	%	2	%	1	%
Asian-Pacific	1	%	2	%	1	%
North American	1	%	3	%	1	%
Emerging markets	1	%	3	%	1	%
Global equities	16	%	6	%	10	%
Global Tactical Asset Allocation	33	%	33	%	41	%
Debt securities (a)	37	%	41	%	38	%
Alternative investments	6	%	6	%	5	%
Total	100	%	100	%	100	%

(a) Includes commingled debt funds.

Schedule of Fair Value of Financial Assets for U.K. Pension Plan Assets

The fair value of assets in the U.K. pension plans by asset class and level within the fair value hierarchy was:

	December 31, 2017								December 31, 2016
			Fair Value Measurement Using								Fair Value Measurement Using
	Total		Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3
Cash and cash equivalents	$	216	$	216	$	—	$	—	$	42	$	42	$	—	$	—
Equity securities measured at NAV (a) :
U.K. companies	157		—		—		—		210		—		—		—
European companies (excluding the U.K.)	98		—		—		—		177		—		—		—
Asian-Pacific companies	60		—		—		—		140		—		—		—
North American companies	123		—		—		—		227		—		—		—
Emerging markets companies	62		—		—		—		209		—		—		—
Global Equities	1,335		—		—		—		466		—		—		—
Other	2,807		—		—		—		2,363		—		—		—
Debt Securities:
U.K. corporate bonds	3		—		3		—		2		—		2		—
U.K. gilts	3,137		—		3,137		—		2,940		—		2,940		—
Alternative investments:
Real estate measured at NAV (a)	492		—		—		—		435		—		—		—
Fair value - U.K. pension plans	$	8,490	$	216	$	3,140	$	—	$	7,211	$	42	$	2,942	$	—

(a) In accordance with accounting guidance certain investments that are measured at fair value using the net asset value per share (NAV), or its equivalent, practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in the table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the statement of financial position.

Schedule of Expected Cash Flows - U.S. Defined Benefit Plans - Expected Payments and Related Federal Subsidy

The following benefit payments, which reflect expected future service, as appropriate, are expected to be paid by the plans and the following federal subsidy payments are expected to be received by PPL.

			Other Postretirement
	Pension		Benefit Payment		Expected Federal Subsidy
2018	$	260	$	51	$	1
2019	269		51		—
2020	268		50		1
2021	270		49		—
2022	272		48		—
2023-2027	1,328		218		2

Schedule of Expected Cash Flows - U.K. Pension Plans - Expected Payments

The following benefit payments, which reflect expected future service, as appropriate, are expected to be paid by the plans.

	Pension
2018	$	343
2019	349
2020	353
2021	356
2022	362
2023-2027	1,843

Expected Employer Contributions to U.S. Savings Plans

Substantially all employees of PPL's subsidiaries are eligible to participate in deferred savings plans (401(k)s). Employer contributions to the plans were:

	2017		2016		2015
PPL	$	36	$	35	$	34
PPL Electric	6		6		6
LKE	18		17		16
LG&E	5		5		5
KU	4		4		4

PPL Electric Utilities Corp [Member]

Defined Benefit Plan Disclosure [Line Items]

Schedule of Funded Status of Defined Benefit Plans

Allocations to PPL Electric resulted in liabilities at December 31 as follows:

	2017		2016
Pension	$	246	$	281
Other postretirement benefits	62		72

LG And E And KU Energy LLC [Member]

Defined Benefit Plan Disclosure [Line Items]

Schedule Of Net Periodic Defined Benefit Costs (Credits)

The following table provides the components of net periodic defined benefit costs for LKE's pension and other postretirement benefit plans for the years ended December 31.

	Pension Benefits									Other Postretirement Benefits
	2017			2016			2015			2017			2016			2015
Net periodic defined benefit costs (credits):
Service cost	$	24		$	23		$	26		$	4		$	5		$	5
Interest cost	68			71			68			9			9			9
Expected return on plan assets	(92		)	(91		)	(88		)	(7		)	(6		)	(6		)
Amortization of:
Prior service cost	8			8			7			1			3			3
Actuarial (gain) loss (a)	31			21			37			—			(1		)	—
Net periodic defined benefit costs (b)	$	39		$	32		$	50		$	7		$	10		$	11
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross:
Net (gain) loss	$	30		$	119		$	20		$	(14	)	$	6		$	(15	)
Prior service cost	7			—			19			8			—			—
Amortization of:
Prior service credit	(8		)	(8		)	(7		)	(1		)	(3		)	(3		)
Actuarial gain (loss)	(32		)	(21		)	(37		)	—			1			—
Total recognized in OCI and regulatory assets/liabilities	(3		)	90			(5		)	(7		)	4			(18		)
Total recognized in net periodic defined benefit costs, OCI and regulatory assets/liabilities	$	36		$	122		$	45		$	—		$	14		$	(7	)

(a) As a result of the 2014 Kentucky rate case settlement that became effective July 1, 2015, the difference between actuarial (gain)/loss calculated in accordance with LKE's pension accounting policy and actuarial (gain)/loss calculated using a 15 year amortization period was $11 million in 2017, $6 million in 2016 and $9 million in 2015.

(b) Due to the amount of lump sum payment distributions from the LG&E qualified pension plan, a settlement charge of $5 million was incurred. In accordance with existing regulatory accounting treatment, LG&E has maintained the settlement charge in regulatory assets. The amount will be amortized in accordance with existing regulatory practice.

Schedule of Amounts Recognized in Other Comprehensive Income and Regulatory Assets and Liabilities

For LKE's pension and other postretirement benefits, the amounts recognized in OCI and regulatory assets/liabilities for the years ended December 31 were as follows:

	Pension Benefits								Other Postretirement Benefits
	2017			2016		2015			2017			2016		2015
OCI	$	33		$	42	$	4		$	(2	)	$	2	$	(2	)
Regulatory assets/liabilities	(36		)	48		(9		)	(5		)	2		(16		)
Total recognized in OCI and regulatory assets/liabilities	$	(3	)	$	90	$	(5	)	$	(7	)	$	4	$	(18	)

Schedule of Amounts to be Amortized from AOCI and Regulatory Assets/Liabilities in Next Fiscal Year

The estimated amounts to be amortized from AOCI and regulatory assets/liabilities into net periodic defined benefit costs for LKE in 2018 are as follows.

	Pension Benefits		Other Postretirement Benefits
Prior service cost	$	9	$	1
Actuarial Loss	39		—
Total	$	48	$	1
Amortization from Balance Sheet:
AOCI	$	11	$	—
Regulatory assets/liabilities	37		1
Total	$	48	$	1

Defined Benefit Plan Assumptions and Impact of One Point Change on Postretirement Plans

The following weighted-average assumptions were used in the valuation of the benefit obligations at December 31. The U.K. pension benefits apply to PPL only.

	Pension Benefits
	U.S.				U.K.				Other Postretirement Benefits
	2017		2016		2017		2016		2017		2016
PPL
Discount rate	3.70	%	4.21	%	2.65	%	2.87	%	3.64	%	4.11	%
Rate of compensation increase	3.78	%	3.95	%	3.50	%	3.50	%	3.75	%	3.92	%
LKE
Discount rate	3.69	%	4.19	%					3.65	%	4.12	%
Rate of compensation increase	3.50	%	3.50	%					3.50	%	3.50	%
LG&E
Discount rate	3.65	%	4.13	%

The following weighted-average assumptions were used to determine the net periodic defined benefit costs for the years ended December 31. The U.K. pension benefits apply to PPL only.

	Pension Benefits
	U.S.						U.K.						Other Postretirement Benefits
	2017		2016		2015		2017		2016		2015		2017		2016		2015
PPL
Discount rate service cost (b)	4.21	%	4.59	%	4.25	%	2.99	%	3.90	%	3.85	%	4.11	%	4.48	%	4.09	%
Discount rate interest cost (b)	4.21	%	4.59	%	4.25	%	2.41	%	3.14	%	3.85	%	4.11	%	4.48	%	4.09	%
Rate of compensation increase	3.95	%	3.93	%	3.91	%	3.50	%	4.00	%	4.00	%	3.92	%	3.91	%	3.86	%
Expected return on plan assets (a)	7.00	%	7.00	%	7.00	%	7.22	%	7.20	%	7.19	%	6.21	%	6.11	%	6.06	%
LKE
Discount rate	4.19	%	4.56	%	4.25	%							4.12	%	4.49	%	4.06	%
Rate of compensation increase	3.50	%	3.50	%	3.50	%							3.50	%	3.50	%	3.50	%
Expected return on plan assets (a)	7.00	%	7.00	%	7.00	%							6.82	%	6.82	%	6.82	%

	Pension Benefits
	U.S.						U.K.			Other Postretirement Benefits
	2017		2016		2015		2017	2016	2015	2017	2016	2015
LG&E
Discount rate	4.13	%	4.49	%	4.20	%
Expected return on plan assets (a)	7.00	%	7.00	%	7.00	%

(a) The expected long-term rates of return for pension and other postretirement benefits are based on management's projections using a best-estimate of expected returns, volatilities and correlations for each asset class. Each plan's specific current and expected asset allocations are also considered in developing a reasonable return assumption.

(b) As of January 1, 2016, WPD began using individual spot rates from the yield curve used to discount the benefit obligation to measure service cost and interest cost. PPL's U.S. plans use a single discount rate derived from an individual bond matching model to measure the benefit obligation, service cost and interest cost. See Note 1 for additional details.

(PPL and LKE)

The following table provides the assumed health care cost trend rates for the years ended December 31:

	2017		2016		2015
PPL and LKE
Health care cost trend rate assumed for next year
– obligations	6.6	%	7.0	%	6.8	%
– cost	7.0	%	6.8	%	7.2	%
Rate to which the cost trend rate is assumed to decline (the ultimate trend rate)
– obligations	5.0	%	5.0	%	5.0	%
– cost	5.0	%	5.0	%	5.0	%
Year that the rate reaches the ultimate trend rate
– obligations	2022		2022		2020
– cost	2022		2020		2020

A one percentage point change in the assumed health care costs trend rate assumption would have had the following effects on the other postretirement benefit plans in 2017:

	One Percentage Point
	Increase		Decrease
Effect on accumulated postretirement benefit obligation
PPL	$	4	$	(4	)
LKE	3		(3		)

Schedule of Funded Status of Defined Benefit Plans

The funded status of LKE's plans at December 31 was as follows:

	Pension Benefits						Other Postretirement Benefits
	2017			2016			2017			2016
Change in Benefit Obligation
Benefit Obligation, beginning of period	$	1,669		$	1,588		$	220		$	216
Service cost	24			23			4			5
Interest cost	68			71			9			9
Participant contributions	—			—			8			7
Plan amendments (a)	6			—			8			—
Actuarial (gain) loss	113			96			(7		)	4
Gross benefits paid (a)	(109		)	(109		)	(19		)	(21		)
Benefit Obligation, end of period	1,771			1,669			223			220
Change in Plan Assets
Plan assets at fair value, beginning of period	1,315			1,289			98			88
Actual return on plan assets	175			69			14			4
Employer contributions	21			66			15			20
Participant contributions	—			—			8			7
Gross benefits paid	(109		)	(109		)	(19		)	(21		)
Plan assets at fair value, end of period	1,402			1,315			116			98
Funded Status, end of period	$	(369	)	$	(354	)	$	(107	)	$	(122	)
Amounts recognized in the Balance Sheets consist of:
Noncurrent asset	$	—		$	—		$	2		$	2
Current liability	(4		)	(4		)	(3		)	(3		)
Noncurrent liability	(365		)	(350		)	(106		)	(121		)
Net amount recognized, end of period	$	(369	)	$	(354	)	$	(107	)	$	(122	)
Amounts recognized in AOCI and regulatory assets/liabilities (pre-tax) consist of:
Prior service cost	$	44		$	45		$	13		$	6
Net actuarial (gain) loss	434			436			(26		)	(13		)
Total	$	478		$	481		$	(13	)	$	(7	)
Total accumulated benefit obligation for defined benefit pension plans	$	1,616		$	1,531

(a) The pension plans were amended in December 2015 to allow active participants and terminated vested participants who had not previously elected a form of payment of their benefit to elect to receive their accrued pension benefit as a one-time lump-sum payment effective January 1, 2016. The projected benefit obligation at December 31, 2016 increased by $19 million as a result of the amendment. Gross benefits paid by the plans include lump-sum cash payments made to participants during 2017 and 2016 of $50 million and $53 million in connection with these offerings.

The amounts recognized in AOCI and regulatory assets/liabilities at December 31 were as follows:

	Pension Benefits				Other Postretirement Benefits
	2017		2016		2017			2016
AOCI	$	144	$	111	$	6		$	8
Regulatory assets/liabilities	334		370		(19		)	(15		)
Total	$	478	$	481	$	(13	)	$	(7	)

Schedule of Projected or Accumulated Benefit Obligations In Excess of Plan Assets

The following tables provide information on pension plans where the projected benefit obligation (PBO) or accumulated benefit obligations (ABO) exceed the fair value of plan assets: 

	PBO in excess of plan assets
	2017		2016
Projected benefit obligation	$	1,771	$	1,669
Fair value of plan assets	1,402		1,315
	ABO in excess of plan assets
	2017		2016
Accumulated benefit obligation	$	1,616	$	1,531
Fair value of plan assets	1,402		1,315

Schedules of Asset Allocation of U.S. Pension Trusts Assets

The asset allocation for the trust and the target allocation by portfolio at December 31 are as follows:

	Percentage of trust assets				2017
	2017 (a)		2016		Target Asset Allocation (a)
Growth Portfolio	56	%	52	%	55	%
Equity securities	32	%	30	%
Debt securities (b)	14	%	12	%
Alternative investments	10	%	10	%
Immunizing Portfolio	43	%	46	%	43	%
Debt securities (b)	39	%	43	%
Derivatives	4	%	3	%
Liquidity Portfolio	1	%	2	%	2	%
Total	100	%	100	%	100	%

(a) Allocations exclude consideration of a group annuity contract held by the LG&E and KU Retirement Plan.

(b) Includes commingled debt funds, which PPL treats as debt securities for asset allocation purposes.

Schedule of Fair Value of Financial Assets for U.S. Pension Plan Assets

The fair value of net assets in the Master Trust by asset class and level within the fair value hierarchy was:

	December 31, 2017								December 31, 2016
			Fair Value Measurements Using								Fair Value Measurements Using
	Total		Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3
PPL Services Corporation Master Trust
Cash and cash equivalents	$	301	$	301	$	—	$	—	$	181	$	181	$	—	$	—
Equity securities:
U.S. Equity	229		229		—		—		152		152		—		—
U.S. Equity fund measured at NAV (a)	364		—		—		—		272		—		—		—
International equity fund at NAV (a)	538		—		—		—		551		—		—		—
Commingled debt measured at NAV (a)	611		—		—		—		546		—		—		—

	December 31, 2017									December 31, 2016
				Fair Value Measurements Using									Fair Value Measurements Using
	Total			Level 1		Level 2		Level 3		Total			Level 1		Level 2		Level 3
Debt securities:
U.S. Treasury and U.S. government sponsored agency	186			186		—		—		381			381		—		—
Corporate	883			—		870		13		850			—		837		13
Other	10			—		10		—		8			—		8		—
Alternative investments:
Real estate measured at NAV (a)	109			—		—		—		102			—		—		—
Private equity measured at NAV (a)	80			—		—		—		80			—		—		—
Hedge funds measured at NAV (a)	175			—		—		—		167			—		—		—
Derivatives:
Interest rate swaps and swaptions	50			—		50		—		61			—		61		—
Other	1			—		1		—		3			—		3		—
Insurance contracts	24			—		—		24		27			—		—		27
PPL Services Corporation Master Trust assets, at fair value	3,561			$	716	$	931	$	37	3,381			$	714	$	909	$	40
Receivables and payables, net (b)	72									(15		)
401(h) accounts restricted for other postretirement benefit obligations	(145		)							(123		)
Total PPL Services Corporation Master Trust pension assets	$	3,488								$	3,243

(a) In accordance with accounting guidance certain investments that are measured at fair value using the net asset value per share (NAV), or its equivalent, practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in the table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the statement of financial position.

(b) Receivables and payables represent amounts for investments sold/purchased but not yet settled along with interest and dividends earned but not yet received.

Reconciliation of U.S. Pension Trust Assets Classified as Level 3 Included in Earnings

A reconciliation of the Master Trust assets classified as Level 3 at December 31, 2017 is as follows:

	Corporate debt		Insurance contracts			Total
Balance at beginning of period	$	13	$	27		$	40
Actual return on plan assets
Relating to assets still held at the reporting date	—		1			1
Purchases, sales and settlements	—		(4		)	(4		)
Balance at end of period	$	13	$	24		$	37

A reconciliation of the Master Trust assets classified as Level 3 at December 31, 2016 is as follows: 

	Corporate debt		Insurance contracts			Total
Balance at beginning of period	$	10	$	32		$	42
Actual return on plan assets
Relating to assets still held at the reporting date	—		1			1
Purchases, sales and settlements	3		(6		)	(3		)
Balance at end of period	$	13	$	27		$	40

Schedule of Fair Value of Financial Assets for U.S. Postretirement Benefits

The fair value of assets in the U.S. other postretirement benefit plans by asset class and level within the fair value hierarchy was:

	December 31, 2017								December 31, 2016
			Fair Value Measurement Using								Fair Value Measurement Using
	Total		Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3
Money market funds	$	10	$	10	$	—	$	—	$	5	$	5	$	—	$	—
U.S. Equity securities:
Large-cap equity fund measure at NAV (a)	123		—		—		—		123		—		—		—
Commingled debt fund measured at NAV (a)	96		—		—		—		114		—		—		—
Debt securities:
Corporate bonds	30		—		30		—		—		—		—		—
Municipalities	—		—		—		—		12		—		12		—
Total VEBA trust assets, at fair value	259		$	10	$	30	$	—	254		$	5	$	12	$	—
Receivables and payables, net (b)	1								1
401(h) account assets	145								123
Total other postretirement benefit plan assets	$	405							$	378

(a) In accordance with accounting guidance certain investments that are measured at fair value using the net asset value per share (NAV), or its equivalent, practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in the table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the statement of financial position.

(b) Receivables and payables represent amounts for investments sold/purchased but not yet settled along with interest and dividends earned but not yet received.

Schedule of Expected Cash Flows - U.S. Defined Benefit Plans - Expected Payments and Related Federal Subsidy

The following benefit payments, which reflect expected future service, as appropriate, are expected to be paid by the plans and the following federal subsidy payments are expected to be received by LKE.

			Other Postretirement
	Pension		Benefit Payment		Expected Federal Subsidy
2018	$	109	$	14	$	—
2019	113		15		—
2020	114		16		1
2021	115		16		—
2022	116		16		—
2023-2027	573		79		2

Louisville Gas And Electric Co [Member]

Defined Benefit Plan Disclosure [Line Items]

Schedule Of Net Periodic Defined Benefit Costs (Credits)

The following table provides the components of net periodic defined benefit costs for LG&E's pension benefit plan for the years ended December 31.

	Pension Benefits
	2017			2016			2015
Net periodic defined benefit costs (credits):
Service cost	$	1		$	1		$	1
Interest cost	13			15			14
Expected return on plan assets	(22		)	(21		)	(20		)
Amortization of:
Prior service cost	5			4			3
Actuarial loss (a)	9			7			11
Net periodic defined benefit costs (b)	$	6		$	6		$	9
Other Changes in Plan Assets and Benefit Obligations Recognized in Regulatory Assets - Gross:
Net (gain) loss	$	(9	)	$	22		$	8
Prior service cost	7			—			10
Amortization of:
Prior service credit	(5		)	(4		)	(3		)
Actuarial gain	(9		)	(7		)	(11		)
Total recognized in regulatory assets/liabilities	(16		)	11			4
Total recognized in net periodic defined benefit costs and regulatory assets	$	(10	)	$	17		$	13

(a) As a result of the 2014 Kentucky rate case settlement that became effective July 1, 2015, the difference between actuarial (gain)/loss calculated in accordance with LG&E's pension accounting policy and actuarial (gain)/loss calculated using a 15 year amortization period was $7 million in 2017, $5 million in 2016 and $3 million in 2015.

(b) Due to the amount of lump sum payment distributions from the LG&E qualified pension plan, a settlement charge of $5 million was incurred. In accordance with existing regulatory accounting treatment, LG&E has maintained the settlement charge in regulatory assets. The amount will be amortized in accordance with existing regulatory practice.

Schedule of Amounts to be Amortized from AOCI and Regulatory Assets/Liabilities in Next Fiscal Year

The estimated amounts to be amortized from regulatory assets into net periodic defined benefit costs for LG&E in 2018 are as follows.

	Pension Benefits
Prior service cost	$	5
Actuarial loss	9
Total	$	14

Schedule of Net Periodic Defined Benefit Costs Included in Income Statement

In the table above, LG&E amounts include costs for the specific plans it sponsors and the following allocated costs of defined benefit plans sponsored by LKE. LG&E is also allocated costs of defined benefit plans from LKS for defined benefit plans sponsored by LKE. See Note 14 for additional information on costs allocated to LG&E from LKS. These allocations are based on LG&E's participation in those plans, which management believes are reasonable:

	Pension Benefits						Other Postretirement Benefits
	2017		2016		2015		2017		2016		2015
LG&E Non-Union Only	$	5	$	4	$	5	$	3	$	3	$	4

Defined Benefit Plan Assumptions and Impact of One Point Change on Postretirement Plans

The following weighted-average assumptions were used in the valuation of the benefit obligations at December 31. The U.K. pension benefits apply to PPL only.

	Pension Benefits
	U.S.				U.K.				Other Postretirement Benefits
	2017		2016		2017		2016		2017		2016
PPL
Discount rate	3.70	%	4.21	%	2.65	%	2.87	%	3.64	%	4.11	%
Rate of compensation increase	3.78	%	3.95	%	3.50	%	3.50	%	3.75	%	3.92	%
LKE
Discount rate	3.69	%	4.19	%					3.65	%	4.12	%
Rate of compensation increase	3.50	%	3.50	%					3.50	%	3.50	%
LG&E
Discount rate	3.65	%	4.13	%

The following weighted-average assumptions were used to determine the net periodic defined benefit costs for the years ended December 31. The U.K. pension benefits apply to PPL only.

	Pension Benefits
	U.S.						U.K.						Other Postretirement Benefits
	2017		2016		2015		2017		2016		2015		2017		2016		2015
PPL
Discount rate service cost (b)	4.21	%	4.59	%	4.25	%	2.99	%	3.90	%	3.85	%	4.11	%	4.48	%	4.09	%
Discount rate interest cost (b)	4.21	%	4.59	%	4.25	%	2.41	%	3.14	%	3.85	%	4.11	%	4.48	%	4.09	%
Rate of compensation increase	3.95	%	3.93	%	3.91	%	3.50	%	4.00	%	4.00	%	3.92	%	3.91	%	3.86	%
Expected return on plan assets (a)	7.00	%	7.00	%	7.00	%	7.22	%	7.20	%	7.19	%	6.21	%	6.11	%	6.06	%
LKE
Discount rate	4.19	%	4.56	%	4.25	%							4.12	%	4.49	%	4.06	%
Rate of compensation increase	3.50	%	3.50	%	3.50	%							3.50	%	3.50	%	3.50	%
Expected return on plan assets (a)	7.00	%	7.00	%	7.00	%							6.82	%	6.82	%	6.82	%

	Pension Benefits
	U.S.						U.K.			Other Postretirement Benefits
	2017		2016		2015		2017	2016	2015	2017	2016	2015
LG&E
Discount rate	4.13	%	4.49	%	4.20	%
Expected return on plan assets (a)	7.00	%	7.00	%	7.00	%

(a) The expected long-term rates of return for pension and other postretirement benefits are based on management's projections using a best-estimate of expected returns, volatilities and correlations for each asset class. Each plan's specific current and expected asset allocations are also considered in developing a reasonable return assumption.

(b) As of January 1, 2016, WPD began using individual spot rates from the yield curve used to discount the benefit obligation to measure service cost and interest cost. PPL's U.S. plans use a single discount rate derived from an individual bond matching model to measure the benefit obligation, service cost and interest cost. See Note 1 for additional details.

Schedule of Funded Status of Defined Benefit Plans

(LG&E)

The funded status of LG&E's plan at December 31, was as follows:

	Pension Benefits
	2017			2016
Change in Benefit Obligation
Benefit Obligation, beginning of period	$	329		$	326
Service cost	1			1
Interest cost	13			15
Plan amendments (a)	6			—
Actuarial (gain) loss	11			15
Gross benefits paid (a)	(34		)	(28		)
Benefit Obligation, end of period	326			329
Change in Plan Assets
Plan assets at fair value, beginning of period	318			297
Actual return on plan assets	41			14
Employer contributions	—			35
Gross benefits paid	(34		)	(28		)
Plan assets at fair value, end of period	325			318
Funded Status, end of period	$	(1	)	$	(11	)
Amounts recognized in the Balance Sheets consist of:
Noncurrent liability	$	(1	)	$	(11	)
Net amount recognized, end of period	$	(1	)	$	(11	)
Amounts recognized in regulatory assets (pre-tax) consist of:
Prior service cost	$	27		$	25
Net actuarial loss	92			110
Total	$	119		$	135
Total accumulated benefit obligation for defined benefit pension plan	$	326		$	329

(a) The pension plan was amended in December 2015 to allow active participants and terminated vested participants who had not previously elected a form of payment of their benefit to elect to receive their accrued pension benefit as a one-time lump-sum payment effective January 1, 2016. The projected benefit obligation at December 31, 2015 increased by $10 million as a result of the amendment. Gross benefits paid by the plan include lump-sum cash payments made to participants during 2017 and 2016 of$19 million and $14 million in connection with this offering.

Allocations to LG&E resulted in liabilities at December 31 as follows:

	2017		2016
Pension	$	44	$	42
Other postretirement benefits	74		76

Schedules of Asset Allocation of U.S. Pension Trusts Assets

The asset allocation for the trust and the target allocation by portfolio at December 31 are as follows:

	Percentage of trust assets				2017
	2017 (a)		2016		Target Asset Allocation (a)
Growth Portfolio	56	%	52	%	55	%
Equity securities	32	%	30	%
Debt securities (b)	14	%	12	%
Alternative investments	10	%	10	%
Immunizing Portfolio	43	%	46	%	43	%
Debt securities (b)	39	%	43	%
Derivatives	4	%	3	%
Liquidity Portfolio	1	%	2	%	2	%
Total	100	%	100	%	100	%

(a) Allocations exclude consideration of a group annuity contract held by the LG&E and KU Retirement Plan.

(b) Includes commingled debt funds, which PPL treats as debt securities for asset allocation purposes.

Schedule of Fair Value of Financial Assets for U.S. Pension Plan Assets

The fair value of net assets in the Master Trust by asset class and level within the fair value hierarchy was:

	December 31, 2017								December 31, 2016
			Fair Value Measurements Using								Fair Value Measurements Using
	Total		Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3
PPL Services Corporation Master Trust
Cash and cash equivalents	$	301	$	301	$	—	$	—	$	181	$	181	$	—	$	—
Equity securities:
U.S. Equity	229		229		—		—		152		152		—		—
U.S. Equity fund measured at NAV (a)	364		—		—		—		272		—		—		—
International equity fund at NAV (a)	538		—		—		—		551		—		—		—
Commingled debt measured at NAV (a)	611		—		—		—		546		—		—		—

	December 31, 2017									December 31, 2016
				Fair Value Measurements Using									Fair Value Measurements Using
	Total			Level 1		Level 2		Level 3		Total			Level 1		Level 2		Level 3
Debt securities:
U.S. Treasury and U.S. government sponsored agency	186			186		—		—		381			381		—		—
Corporate	883			—		870		13		850			—		837		13
Other	10			—		10		—		8			—		8		—
Alternative investments:
Real estate measured at NAV (a)	109			—		—		—		102			—		—		—
Private equity measured at NAV (a)	80			—		—		—		80			—		—		—
Hedge funds measured at NAV (a)	175			—		—		—		167			—		—		—
Derivatives:
Interest rate swaps and swaptions	50			—		50		—		61			—		61		—
Other	1			—		1		—		3			—		3		—
Insurance contracts	24			—		—		24		27			—		—		27
PPL Services Corporation Master Trust assets, at fair value	3,561			$	716	$	931	$	37	3,381			$	714	$	909	$	40
Receivables and payables, net (b)	72									(15		)
401(h) accounts restricted for other postretirement benefit obligations	(145		)							(123		)
Total PPL Services Corporation Master Trust pension assets	$	3,488								$	3,243

(a) In accordance with accounting guidance certain investments that are measured at fair value using the net asset value per share (NAV), or its equivalent, practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in the table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the statement of financial position.

(b) Receivables and payables represent amounts for investments sold/purchased but not yet settled along with interest and dividends earned but not yet received.

Reconciliation of U.S. Pension Trust Assets Classified as Level 3 Included in Earnings

A reconciliation of the Master Trust assets classified as Level 3 at December 31, 2017 is as follows:

	Corporate debt		Insurance contracts			Total
Balance at beginning of period	$	13	$	27		$	40
Actual return on plan assets
Relating to assets still held at the reporting date	—		1			1
Purchases, sales and settlements	—		(4		)	(4		)
Balance at end of period	$	13	$	24		$	37

A reconciliation of the Master Trust assets classified as Level 3 at December 31, 2016 is as follows: 

	Corporate debt		Insurance contracts			Total
Balance at beginning of period	$	10	$	32		$	42
Actual return on plan assets
Relating to assets still held at the reporting date	—		1			1
Purchases, sales and settlements	3		(6		)	(3		)
Balance at end of period	$	13	$	27		$	40

Schedule of Expected Cash Flows - U.S. Defined Benefit Plans - Expected Payments and Related Federal Subsidy

The following benefit payments, which reflect expected future service, as appropriate, are expected to be paid by the plan.

	Pension
2018	$	26
2019	26
2020	26
2021	25
2022	24
2023-2027	104

Kentucky Utilities Co [Member]

Defined Benefit Plan Disclosure [Line Items]

Schedule of Funded Status of Defined Benefit Plans

Allocations to KU resulted in liabilities at December 31 as follows.

	2017		2016
Pension	$	36	$	62
Other postretirement benefits	32		40