Retirement and Postemployment Benefits (Weighted-Average Assumptions, Cost Trend Rates and Funded Status) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Amounts recognized in the Balance Sheets consist of: [Abstract]
Noncurrent asset	$ 535	$ 284
Pension Plan [Member] | U.S. [Member]
Weighted Average Assumptions Used in the Valuation of the Benefit Obligations (Details) [Abstract]
Benefit obligations valuation discount rate	4.35%	3.70%
Benefit obligations valuation rate of compensation increase	3.79%	3.78%
Weighted Average Assumptions Used to Determine the Net Periodic Benefit Costs (Details) [Abstract]
Net periodic benefit costs discount rate - service cost	3.70%	4.21%	4.59%
Net periodic benefit costs discount rate - interest cost	3.70%	4.21%	4.59%
Net periodic benefit costs rate of compensation increase	3.78%	3.95%	3.93%
Net periodic benefit costs expected return on plan assets	7.25%	7.00%	7.00%
Assumed Health Care Cost Trend Rates (Details) [Abstract]
Health care cost trend rate assumed for next year, obligations	6.60%	6.60%	7.00%
Health care cost trend rate assumed for next year, cost	6.60%	7.00%	6.80%
Rate to which the cost trend rate is assumed to decline (the ultimate trend rate), obligations	5.00%	5.00%	5.00%
Rate to which the cost trend rate is assumed to decline (the ultimate trend rate), cost	5.00%	5.00%	5.00%
Year that the rate reaches the ultimate trend rate, obligations	2023	2022	2022
Year that the rate reaches the ultimate trend rate, cost	2022	2022	2020
Change in Benefit Obligation [Roll Forward]
Benefit Obligation, beginning of period	$ 4,288	$ 4,079
Service cost	62	65	$ 66
Interest cost	156	168	174
Participant contributions	0	0
Plan Amendments	1	(1)
Actuarial (gain) loss	(352)	233
Settlements	0	(6)
Termination benefits	0	1
Gross benefits paid	(272)	(251)
Federal subsidy	0	0
Currency conversion	0	0
Benefit Obligation, end of period	3,883	4,288	4,079
Change in Plan Assets [Roll Forward]
Balance at beginning of period	3,488	3,243
Actual return on plan assets	(260)	437
Employer contributions	153	65
Participant contributions	0	0
Transfer out	0	0
Settlements	0	(6)
Gross benefits paid	(272)	(251)
Currency conversion	0	0
Balance at end of period	3,109	3,488	$ 3,243
Funded Status, end of period	(774)	(800)
Amounts recognized in the Balance Sheets consist of: [Abstract]
Noncurrent asset	0	0
Current liability	(13)	(13)
Noncurrent liability	(761)	(787)
Net amount recognized, end of period	(774)	(800)
Amounts recognized in AOCI and regulatory assets/liabilities (pre-tax): [Abstract]
Prior service cost (credit)	40	49
Net actuarial (gain) loss	1,207	1,134
Total	1,247	1,183
Total accumulated benefit obligation for defined benefit pension plans	3,668	4,000
Changes in Plan Assets and Benefit Obligations Recognized in AOCI and Regulatory Assets/Liabilities by Type (Details) [Abstract]
AOCI	370	374
Regulatory assets/liabilities	877	809
Total	1,247	1,183
Pension Plans Where the Projected or Accumulated Benefit Obligation Exceed the Fair Value of Plan Assets (Details) [Abstract]
Projected benefit obligations	3,883	4,288
Fair value of plan assets where the projected benefit obligations exceed the value of plan assets	3,109	3,488
Accumulated benefit obligation	3,668	4,000
Fair value of plan assets where the accumulated benefit obligations exceed the value of plan assets	$ 3,109	$ 3,488
Pension Plan [Member] | U.K. [Member]
Weighted Average Assumptions Used in the Valuation of the Benefit Obligations (Details) [Abstract]
Benefit obligations valuation discount rate	2.98%	2.65%
Benefit obligations valuation rate of compensation increase	3.50%	3.50%
Weighted Average Assumptions Used to Determine the Net Periodic Benefit Costs (Details) [Abstract]
Net periodic benefit costs discount rate - service cost	2.73%	2.99%	3.90%
Net periodic benefit costs discount rate - interest cost	2.31%	2.41%	3.14%
Net periodic benefit costs rate of compensation increase	3.50%	3.50%	4.00%
Net periodic benefit costs expected return on plan assets	7.23%	7.22%	7.20%
Change in Benefit Obligation [Roll Forward]
Benefit Obligation, beginning of period	$ 8,219	$ 7,383
Service cost	82	76	$ 69
Interest cost	185	178	235
Participant contributions	13	13
Plan Amendments	12	0
Actuarial (gain) loss	(406)	293
Settlements	0	(1)
Termination benefits	0	0
Gross benefits paid	(381)	(345)
Federal subsidy	0	0
Currency conversion	(449)	622
Benefit Obligation, end of period	7,275	8,219	7,383
Change in Plan Assets [Roll Forward]
Balance at beginning of period	8,490	7,211
Actual return on plan assets	(30)	480
Employer contributions	188	486
Participant contributions	13	13
Transfer out	0	0
Settlements	0	(1)
Gross benefits paid	(381)	(345)
Currency conversion	(479)	646
Balance at end of period	7,801	8,490	$ 7,211
Funded Status, end of period	526	271
Amounts recognized in the Balance Sheets consist of: [Abstract]
Noncurrent asset	535	284
Current liability	(1)	0
Noncurrent liability	(8)	(13)
Net amount recognized, end of period	526	271
Amounts recognized in AOCI and regulatory assets/liabilities (pre-tax): [Abstract]
Prior service cost (credit)	12	0
Net actuarial (gain) loss	2,806	2,755
Total	2,818	2,755
Total accumulated benefit obligation for defined benefit pension plans	6,689	7,542
Changes in Plan Assets and Benefit Obligations Recognized in AOCI and Regulatory Assets/Liabilities by Type (Details) [Abstract]
Total	2,818	2,755
Pension Plans Where the Projected or Accumulated Benefit Obligation Exceed the Fair Value of Plan Assets (Details) [Abstract]
Projected benefit obligations	9	3,083
Fair value of plan assets where the projected benefit obligations exceed the value of plan assets	0	3,070
Accumulated benefit obligation	9	10
Fair value of plan assets where the accumulated benefit obligations exceed the value of plan assets	$ 0	$ 0
Other Postretirement Benefits Plan [Member]
Weighted Average Assumptions Used in the Valuation of the Benefit Obligations (Details) [Abstract]
Benefit obligations valuation discount rate	4.31%	3.64%
Benefit obligations valuation rate of compensation increase	3.76%	3.75%
Weighted Average Assumptions Used to Determine the Net Periodic Benefit Costs (Details) [Abstract]
Net periodic benefit costs discount rate - service cost	3.64%	4.11%	4.48%
Net periodic benefit costs discount rate - interest cost	3.64%	4.11%	4.48%
Net periodic benefit costs rate of compensation increase	3.75%	3.92%	3.91%
Net periodic benefit costs expected return on plan assets	6.40%	6.21%	6.11%
Change in Benefit Obligation [Roll Forward]
Benefit Obligation, beginning of period	$ 589	$ 591
Service cost	7	7	$ 7
Interest cost	21	23	26
Participant contributions	13	14
Plan Amendments	0	8
Actuarial (gain) loss	(34)	4
Settlements	0	0
Termination benefits	0	0
Gross benefits paid	(58)	(59)
Federal subsidy	0	1
Currency conversion	0	0
Benefit Obligation, end of period	538	589	591
Change in Plan Assets [Roll Forward]
Balance at beginning of period	405	378
Actual return on plan assets	(20)	54
Employer contributions	23	15
Participant contributions	11	13
Transfer out	(65)	0
Settlements	0	0
Gross benefits paid	(53)	(55)
Currency conversion	0	0
Balance at end of period	301	405	$ 378
Funded Status, end of period	(237)	(184)
Amounts recognized in the Balance Sheets consist of: [Abstract]
Noncurrent asset	2	2
Current liability	(3)	(3)
Noncurrent liability	(236)	(183)
Net amount recognized, end of period	(237)	(184)
Amounts recognized in AOCI and regulatory assets/liabilities (pre-tax): [Abstract]
Prior service cost (credit)	10	9
Net actuarial (gain) loss	24	16
Total	34	25
Changes in Plan Assets and Benefit Obligations Recognized in AOCI and Regulatory Assets/Liabilities by Type (Details) [Abstract]
AOCI	21	15
Regulatory assets/liabilities	13	10
Total	34	25
PPL Electric Utilities Corp [Member] | Pension Plan [Member] | U.S. [Member] | PPL Services Funded Status Allocation [Member]
Change in Plan Assets [Roll Forward]
Funded Status, end of period	285	246
PPL Electric Utilities Corp [Member] | Other Postretirement Benefits Plan [Member] | PPL Services Funded Status Allocation [Member]
Change in Plan Assets [Roll Forward]
Funded Status, end of period	$ 120	$ 62
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member]
Weighted Average Assumptions Used in the Valuation of the Benefit Obligations (Details) [Abstract]
Benefit obligations valuation discount rate	4.35%	3.69%
Benefit obligations valuation rate of compensation increase	3.50%	3.50%
Weighted Average Assumptions Used to Determine the Net Periodic Benefit Costs (Details) [Abstract]
Net periodic benefit costs discount rate	3.69%	4.19%	4.56%
Net periodic benefit costs rate of compensation increase	3.50%	3.50%	3.50%
Net periodic benefit costs expected return on plan assets	7.25%	7.00%	7.00%
Assumed Health Care Cost Trend Rates (Details) [Abstract]
Health care cost trend rate assumed for next year, obligations	6.60%	6.60%	7.00%
Health care cost trend rate assumed for next year, cost	6.60%	7.00%	6.80%
Rate to which the cost trend rate is assumed to decline (the ultimate trend rate), obligations	5.00%	5.00%	5.00%
Rate to which the cost trend rate is assumed to decline (the ultimate trend rate), cost	5.00%	5.00%	5.00%
Year that the rate reaches the ultimate trend rate, obligations	2023	2022	2022
Year that the rate reaches the ultimate trend rate, cost	2022	2022	2020
Change in Benefit Obligation [Roll Forward]
Benefit Obligation, beginning of period	$ 1,771	$ 1,669
Service cost	25	24	$ 23
Interest cost	63	68	71
Participant contributions	0	0
Plan Amendments	0	6
Actuarial (gain) loss	(168)	113
Gross benefits paid	(111)	(109)
Benefit Obligation, end of period	1,580	1,771	1,669
Defined Benefit Plan One Time Cash Payouts To Terminated Vested Employees	52	50
Change in Plan Assets [Roll Forward]
Balance at beginning of period	1,402	1,315
Actual return on plan assets	(106)	175
Employer contributions	109	21
Participant contributions	0	0
Gross benefits paid	(111)	(109)
Balance at end of period	1,294	1,402	$ 1,315
Funded Status, end of period	(286)	(369)
Amounts recognized in the Balance Sheets consist of: [Abstract]
Noncurrent asset	0	0
Current liability	(4)	(4)
Noncurrent liability	(282)	(365)
Net amount recognized, end of period	(286)	(369)
Amounts recognized in AOCI and regulatory assets/liabilities (pre-tax): [Abstract]
Prior service cost (credit)	35	44
Net actuarial (gain) loss	439	434
Total	474	478
Total accumulated benefit obligation for defined benefit pension plans	1,467	1,616
Changes in Plan Assets and Benefit Obligations Recognized in AOCI and Regulatory Assets/Liabilities by Type (Details) [Abstract]
AOCI	118	144
Regulatory assets/liabilities	356	334
Total	474	478
Pension Plans Where the Projected or Accumulated Benefit Obligation Exceed the Fair Value of Plan Assets (Details) [Abstract]
Projected benefit obligations	1,580	1,771
Fair value of plan assets where the projected benefit obligations exceed the value of plan assets	1,294	1,402
Accumulated benefit obligation	1,467	1,616
Fair value of plan assets where the accumulated benefit obligations exceed the value of plan assets	$ 1,294	$ 1,402
LG And E And KU Energy LLC [Member] | Other Postretirement Benefits Plan [Member]
Weighted Average Assumptions Used in the Valuation of the Benefit Obligations (Details) [Abstract]
Benefit obligations valuation discount rate	4.32%	3.65%
Benefit obligations valuation rate of compensation increase	3.50%	3.50%
Weighted Average Assumptions Used to Determine the Net Periodic Benefit Costs (Details) [Abstract]
Net periodic benefit costs discount rate	3.65%	4.12%	4.49%
Net periodic benefit costs rate of compensation increase	3.50%	3.50%	3.50%
Net periodic benefit costs expected return on plan assets	7.15%	6.82%	6.82%
Change in Benefit Obligation [Roll Forward]
Benefit Obligation, beginning of period	$ 223	$ 220
Service cost	4	4	$ 5
Interest cost	8	9	9
Participant contributions	8	8
Plan Amendments	0	8
Actuarial (gain) loss	(16)	(7)
Gross benefits paid	(22)	(19)
Benefit Obligation, end of period	205	223	220
Change in Plan Assets [Roll Forward]
Balance at beginning of period	116	98
Actual return on plan assets	(9)	14
Employer contributions	24	15
Participant contributions	8	8
Gross benefits paid	(22)	(19)
Balance at end of period	117	116	$ 98
Funded Status, end of period	(88)	(107)
Amounts recognized in the Balance Sheets consist of: [Abstract]
Noncurrent asset	2	2
Current liability	(3)	(3)
Noncurrent liability	(87)	(106)
Net amount recognized, end of period	(88)	(107)
Amounts recognized in AOCI and regulatory assets/liabilities (pre-tax): [Abstract]
Prior service cost (credit)	12	13
Net actuarial (gain) loss	(25)	(26)
Total	(13)	(13)
Changes in Plan Assets and Benefit Obligations Recognized in AOCI and Regulatory Assets/Liabilities by Type (Details) [Abstract]
AOCI	10	6
Regulatory assets/liabilities	(23)	(19)
Total	$ (13)	$ (13)
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member]
Weighted Average Assumptions Used in the Valuation of the Benefit Obligations (Details) [Abstract]
Benefit obligations valuation discount rate	4.33%	3.65%
Weighted Average Assumptions Used to Determine the Net Periodic Benefit Costs (Details) [Abstract]
Net periodic benefit costs discount rate	3.65%	4.13%	4.49%
Net periodic benefit costs expected return on plan assets	7.25%	7.00%	7.00%
Change in Benefit Obligation [Roll Forward]
Benefit Obligation, beginning of period	$ 326	$ 329
Service cost	1	1	$ 1
Interest cost	12	13	15
Plan Amendments	0	6
Actuarial (gain) loss	(24)	11
Gross benefits paid	(30)	(34)
Benefit Obligation, end of period	285	326	329
Defined Benefit Plan One Time Cash Payouts To Terminated Vested Employees	16	19
Change in Plan Assets [Roll Forward]
Balance at beginning of period	325	318
Actual return on plan assets	(24)	41
Employer contributions	10	0
Gross benefits paid	(30)	(34)
Balance at end of period	281	325	$ 318
Funded Status, end of period	(4)	(1)
Amounts recognized in the Balance Sheets consist of: [Abstract]
Noncurrent liability	(4)	(1)
Net amount recognized, end of period	(4)	(1)
Amounts recognized in AOCI and regulatory assets/liabilities (pre-tax): [Abstract]
Prior service cost (credit)	22	27
Net actuarial (gain) loss	(107)	92
Total	129	119
Total accumulated benefit obligation for defined benefit pension plans	285	326
Changes in Plan Assets and Benefit Obligations Recognized in AOCI and Regulatory Assets/Liabilities by Type (Details) [Abstract]
Total	129	119
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | LKE Funded Status Allocation [Member]
Change in Plan Assets [Roll Forward]
Funded Status, end of period	7	44
Louisville Gas And Electric Co [Member] | Other Postretirement Benefits Plan [Member] | LKE Funded Status Allocation [Member]
Change in Plan Assets [Roll Forward]
Funded Status, end of period	65	74
Kentucky Utilities Co [Member] | Pension Plan [Member] | U.S. [Member] | LKE Funded Status Allocation [Member]
Change in Plan Assets [Roll Forward]
Funded Status, end of period	1	36
Kentucky Utilities Co [Member] | Other Postretirement Benefits Plan [Member] | LKE Funded Status Allocation [Member]
Change in Plan Assets [Roll Forward]
Funded Status, end of period	$ 25	$ 32