Retirement and Postemployment Benefits (Weighted-Average Assumptions, Cost Trend Rates and Funded Status) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Amounts recognized in the Balance Sheets consist of: [Abstract]
Noncurrent asset	$ 464	$ 535
Pension Plan [Member] | U.S. [Member]
Weighted Average Assumptions Used in the Valuation of the Benefit Obligations (Details) [Abstract]
Benefit obligations valuation discount rate	3.64%	4.35%
Benefit obligations valuation rate of compensation increase	3.79%	3.79%
Weighted Average Assumptions Used to Determine the Net Periodic Benefit Costs (Details) [Abstract]
Net periodic benefit costs discount rate - service cost	4.35%	3.70%	4.21%
Net periodic benefit costs discount rate - interest cost	4.35%	3.70%	4.21%
Net periodic benefit costs rate of compensation increase	3.79%	3.78%	3.95%
Net periodic benefit costs expected return on plan assets	7.25%	7.25%	7.00%
Assumed Health Care Cost Trend Rates (Details) [Abstract]
Health care cost trend rate assumed for next year, obligations	6.60%	6.60%	6.60%
Health care cost trend rate assumed for next year, cost	6.60%	6.60%	7.00%
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	2024	2023	2022
Year that the rate reaches the ultimate trend rate, cost	2023	2022	2022
Change in Benefit Obligation [Roll Forward]
Benefit Obligation, beginning of period	$ 3,883	$ 4,288
Service cost	50	62	$ 65
Interest cost	164	156	168
Participant contributions	0	0
Plan Amendments	2	1
Actuarial (gain) loss	368	(352)
Settlements	(21)	0
Gross benefits paid	(300)	(272)
Federal subsidy	0	0
Currency conversion	0	0
Benefit Obligation, end of period	4,146	3,883	4,288
Change in Plan Assets [Roll Forward]
Balance at beginning of period	3,109	3,488
Actual return on plan assets	735	(260)
Employer contributions	63	153
Participant contributions	0	0
Transfer out	0	0
Settlements	(22)	0
Gross benefits paid	(300)	(272)
Currency conversion	0	0
Balance at end of period	3,585	3,109	$ 3,488
Funded Status, end of period	(561)	(774)
Amounts recognized in the Balance Sheets consist of: [Abstract]
Noncurrent asset	24	0
Current liability	(8)	(13)
Noncurrent liability	(577)	(761)
Net amount recognized, end of period	(561)	(774)
Amounts recognized in AOCI and regulatory assets/liabilities (pre-tax): [Abstract]
Prior service cost (credit)	34	40
Net actuarial (gain) loss	1,029	1,207
Total	1,063	1,247
Total accumulated benefit obligation for defined benefit pension plans	3,910	3,668
Changes in Plan Assets and Benefit Obligations Recognized in AOCI and Regulatory Assets/Liabilities by Type (Details) [Abstract]
AOCI	352	370
Regulatory assets/liabilities	711	877
Total	1,063	1,247
Pension Plans Where the Projected or Accumulated Benefit Obligation Exceed the Fair Value of Plan Assets (Details) [Abstract]
Projected benefit obligations	3,861	3,883
Fair value of plan assets where the projected benefit obligations exceed the value of plan assets	3,275	3,109
Accumulated benefit obligation	3,624	3,668
Fair value of plan assets where the accumulated benefit obligations exceed the value of plan assets	$ 3,275	$ 3,109
Pension Plan [Member] | U.K. [Member]
Weighted Average Assumptions Used in the Valuation of the Benefit Obligations (Details) [Abstract]
Benefit obligations valuation discount rate	1.94%	2.98%
Benefit obligations valuation rate of compensation increase	3.25%	3.50%
Weighted Average Assumptions Used to Determine the Net Periodic Benefit Costs (Details) [Abstract]
Net periodic benefit costs discount rate - service cost	3.12%	2.73%	2.99%
Net periodic benefit costs discount rate - interest cost	2.62%	2.31%	2.41%
Net periodic benefit costs rate of compensation increase	3.50%	3.50%	3.50%
Net periodic benefit costs expected return on plan assets	7.21%	7.23%	7.22%
Change in Benefit Obligation [Roll Forward]
Benefit Obligation, beginning of period	$ 7,275	$ 8,219
Service cost	68	82	$ 76
Interest cost	187	185	178
Participant contributions	12	13
Plan Amendments	0	12
Actuarial (gain) loss	1,220	(406)
Settlements	0	0
Gross benefits paid	(363)	(381)
Federal subsidy	0	0
Currency conversion	116	(449)
Benefit Obligation, end of period	8,515	7,275	8,219
Change in Plan Assets [Roll Forward]
Balance at beginning of period	7,801	8,490
Actual return on plan assets	1,095	(30)
Employer contributions	278	188
Participant contributions	12	13
Transfer out	0	0
Settlements	0	0
Gross benefits paid	(363)	(381)
Currency conversion	122	(479)
Balance at end of period	8,945	7,801	$ 8,490
Funded Status, end of period	430	526
Amounts recognized in the Balance Sheets consist of: [Abstract]
Noncurrent asset	440	535
Current liability	(1)	(1)
Noncurrent liability	(9)	(8)
Net amount recognized, end of period	430	526
Amounts recognized in AOCI and regulatory assets/liabilities (pre-tax): [Abstract]
Prior service cost (credit)	11	12
Net actuarial (gain) loss	3,435	2,806
Total	3,446	2,818
Total accumulated benefit obligation for defined benefit pension plans	7,821	6,689
Changes in Plan Assets and Benefit Obligations Recognized in AOCI and Regulatory Assets/Liabilities by Type (Details) [Abstract]
Total	3,446	2,818
Pension Plans Where the Projected or Accumulated Benefit Obligation Exceed the Fair Value of Plan Assets (Details) [Abstract]
Projected benefit obligations	10	9
Fair value of plan assets where the projected benefit obligations exceed the value of plan assets	0	0
Accumulated benefit obligation	10	9
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	3.60%	4.31%
Benefit obligations valuation rate of compensation increase	3.76%	3.76%
Weighted Average Assumptions Used to Determine the Net Periodic Benefit Costs (Details) [Abstract]
Net periodic benefit costs discount rate - service cost	4.31%	3.64%	4.11%
Net periodic benefit costs discount rate - interest cost	4.31%	3.64%	4.11%
Net periodic benefit costs rate of compensation increase	3.76%	3.75%	3.92%
Net periodic benefit costs expected return on plan assets	6.46%	6.40%	6.21%
Change in Benefit Obligation [Roll Forward]
Benefit Obligation, beginning of period	$ 538	$ 589
Service cost	6	7	$ 7
Interest cost	22	21	23
Participant contributions	14	13
Plan Amendments	0	0
Actuarial (gain) loss	34	(34)
Settlements	0	0
Gross benefits paid	(58)	(58)
Federal subsidy	1	0
Currency conversion	0	0
Benefit Obligation, end of period	557	538	589
Change in Plan Assets [Roll Forward]
Balance at beginning of period	301	405
Actual return on plan assets	71	(20)
Employer contributions	10	23
Participant contributions	10	11
Transfer out	0	(65)
Settlements	0	0
Gross benefits paid	(52)	(53)
Currency conversion	0	0
Balance at end of period	340	301	$ 405
Funded Status, end of period	(217)	(237)
Amounts recognized in the Balance Sheets consist of: [Abstract]
Noncurrent asset	11	2
Current liability	(2)	(3)
Noncurrent liability	(226)	(236)
Net amount recognized, end of period	(217)	(237)
Amounts recognized in AOCI and regulatory assets/liabilities (pre-tax): [Abstract]
Prior service cost (credit)	10	10
Net actuarial (gain) loss	6	24
Total	16	34
Changes in Plan Assets and Benefit Obligations Recognized in AOCI and Regulatory Assets/Liabilities by Type (Details) [Abstract]
AOCI	13	21
Regulatory assets/liabilities	3	13
Total	16	34
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	179	285
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	$ 122	$ 120
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	3.62%	4.35%
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	4.35%	3.69%	4.19%
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%	7.25%	7.00%
Assumed Health Care Cost Trend Rates (Details) [Abstract]
Health care cost trend rate assumed for next year, obligations	6.60%	6.60%	6.60%
Health care cost trend rate assumed for next year, cost	6.60%	6.60%	7.00%
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	2024	2023	2022
Year that the rate reaches the ultimate trend rate, cost	2023	2022	2022
Change in Benefit Obligation [Roll Forward]
Benefit Obligation, beginning of period	$ 1,580	$ 1,771
Service cost	22	25	$ 24
Interest cost	66	63	68
Participant contributions	0	0
Plan Amendments	2	0
Actuarial (gain) loss	166	(168)
Settlements	(16)	0
Gross benefits paid	(136)	(111)
Benefit Obligation, end of period	1,684	1,580	1,771
Defined Benefit Plan One Time Cash Payouts To Terminated Vested Employees	74	52
Change in Plan Assets [Roll Forward]
Balance at beginning of period	1,294	1,402
Actual return on plan assets	304	(106)
Employer contributions	24	109
Participant contributions	0	0
Settlements	(16)	0
Gross benefits paid	(136)	(111)
Balance at end of period	1,470	1,294	$ 1,402
Funded Status, end of period	(214)	(286)
Amounts recognized in the Balance Sheets consist of: [Abstract]
Noncurrent asset	24	0
Current liability	(5)	(4)
Noncurrent liability	(233)	(282)
Net amount recognized, end of period	(214)	(286)
Amounts recognized in AOCI and regulatory assets/liabilities (pre-tax): [Abstract]
Prior service cost (credit)	30	35
Net actuarial (gain) loss	380	439
Total	410	474
Total accumulated benefit obligation for defined benefit pension plans	1,561	1,467
Changes in Plan Assets and Benefit Obligations Recognized in AOCI and Regulatory Assets/Liabilities by Type (Details) [Abstract]
AOCI	132	118
Regulatory assets/liabilities	278	356
Total	410	474
Pension Plans Where the Projected or Accumulated Benefit Obligation Exceed the Fair Value of Plan Assets (Details) [Abstract]
Projected benefit obligations	1,398	1,580
Fair value of plan assets where the projected benefit obligations exceed the value of plan assets	1,160	1,294
Accumulated benefit obligation	1,276	1,467
Fair value of plan assets where the accumulated benefit obligations exceed the value of plan assets	$ 1,160	$ 1,294
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	3.59%	4.32%
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	4.32%	3.65%	4.12%
Net periodic benefit costs rate of compensation increase	3.50%	3.50%	3.50%
Net periodic benefit costs expected return on plan assets	7.00%	7.15%	6.82%
Change in Benefit Obligation [Roll Forward]
Benefit Obligation, beginning of period	$ 205	$ 223
Service cost	4	4	$ 4
Interest cost	8	8	9
Participant contributions	7	8
Plan Amendments	0	0
Actuarial (gain) loss	5	(16)
Settlements	0	0
Gross benefits paid	(21)	(22)
Benefit Obligation, end of period	208	205	223
Change in Plan Assets [Roll Forward]
Balance at beginning of period	117	116
Actual return on plan assets	27	(9)
Employer contributions	11	24
Participant contributions	7	8
Settlements	0	0
Gross benefits paid	(21)	(22)
Balance at end of period	141	117	$ 116
Funded Status, end of period	(67)	(88)
Amounts recognized in the Balance Sheets consist of: [Abstract]
Noncurrent asset	11	2
Current liability	(2)	(3)
Noncurrent liability	(76)	(87)
Net amount recognized, end of period	(67)	(88)
Amounts recognized in AOCI and regulatory assets/liabilities (pre-tax): [Abstract]
Prior service cost (credit)	10	12
Net actuarial (gain) loss	(37)	(25)
Total	(27)	(13)
Changes in Plan Assets and Benefit Obligations Recognized in AOCI and Regulatory Assets/Liabilities by Type (Details) [Abstract]
AOCI	4	10
Regulatory assets/liabilities	(31)	(23)
Total	$ (27)	$ (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	3.60%	4.33%
Weighted Average Assumptions Used to Determine the Net Periodic Benefit Costs (Details) [Abstract]
Net periodic benefit costs discount rate	4.33%	3.65%	4.13%
Net periodic benefit costs expected return on plan assets	7.25%	7.25%	7.00%
Change in Benefit Obligation [Roll Forward]
Benefit Obligation, beginning of period	$ 285	$ 326
Service cost	1	1	$ 1
Interest cost	11	12	13
Actuarial (gain) loss	25	(24)
Gross benefits paid	(36)	(30)
Benefit Obligation, end of period	286	285	326
Defined Benefit Plan One Time Cash Payouts To Terminated Vested Employees	21	16
Change in Plan Assets [Roll Forward]
Balance at beginning of period	281	325
Actual return on plan assets	64	(24)
Employer contributions	1	10
Gross benefits paid	(36)	(30)
Balance at end of period	310	281	$ 325
Funded Status, end of period	24	(4)
Amounts recognized in the Balance Sheets consist of: [Abstract]
Noncurrent asset	24
Noncurrent liability		(4)
Net amount recognized, end of period	24	(4)
Amounts recognized in AOCI and regulatory assets/liabilities (pre-tax): [Abstract]
Prior service cost (credit)	17	22
Net actuarial (gain) loss	79	107
Total	96	129
Total accumulated benefit obligation for defined benefit pension plans	286	285
Changes in Plan Assets and Benefit Obligations Recognized in AOCI and Regulatory Assets/Liabilities by Type (Details) [Abstract]
Total	96	129
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)	7
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	63	65
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	(31)	1
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	$ 16	$ 25