Retirement and Postemployment Benefits (Weighted-Average Assumptions, Cost Trend Rates and Funded Status) (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Amounts recognized in the Balance Sheets consist of: [Abstract]
Noncurrent asset	$ 706	$ 706	$ 464
Pension Plan [Member] | U.S. [Member]
Weighted Average Assumptions Used in the Valuation of the Benefit Obligations (Details) [Abstract]
Benefit obligations valuation discount rate	2.92%	2.92%	3.64%
Benefit obligations valuation rate of compensation increase	3.76%	3.76%	3.79%
Weighted Average Assumptions Used to Determine the Net Periodic Benefit Costs (Details) [Abstract]
Net periodic benefit costs discount rate - service cost		3.64%	4.35%	3.70%
Net periodic benefit costs discount rate - interest cost		3.64%	4.35%	3.70%
Net periodic benefit costs rate of compensation increase		3.79%	3.79%	3.78%
Net periodic benefit costs expected return on plan assets		7.25%	7.25%	7.25%
Assumed Health Care Cost Trend Rates (Details) [Abstract]
Health care cost trend rate assumed for next year, obligations	6.50%	6.50%	6.60%	6.60%
Health care cost trend rate assumed for next year, cost	6.60%	6.60%	6.60%	6.60%
Rate to which the cost trend rate is assumed to decline (the ultimate trend rate), obligations	5.00%	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%	5.00%
Year that the rate reaches the ultimate trend rate, obligations		2027	2024	2023
Year that the rate reaches the ultimate trend rate, cost		2024	2023	2022
Change in Benefit Obligation [Roll Forward]
Benefit Obligation, beginning of period		$ 4,146	$ 3,883
Service cost		56	50	$ 62
Interest cost		146	164	156
Participant contributions		0	0
Plan Amendments		2	2
Actuarial (gain) loss		256	368
Settlements		(114)	(21)
Gross benefits paid		(241)	(300)
Federal subsidy		0	0
Currency conversion		0	0
Benefit Obligation, end of period	$ 4,251	4,251	4,146	3,883
Change in Plan Assets [Roll Forward]
Balance at beginning of period		3,585	3,109
Actual return on plan assets		723	735
Employer contributions		115	63
Participant contributions		0	0
Settlements		(114)	(22)
Gross benefits paid		(241)	(300)
Currency conversion		0	0
Balance at end of period	4,068	4,068	3,585	$ 3,109
Funded Status, end of period	(183)	(183)	(561)
Amounts recognized in the Balance Sheets consist of: [Abstract]
Noncurrent asset	24	24	24
Current liability	(18)	(18)	(8)
Noncurrent liability	(189)	(189)	(577)
Net amount recognized, end of period	(183)	(183)	(561)
Amounts recognized in AOCI and regulatory assets/liabilities (pre-tax): [Abstract]
Prior service cost (credit)	27	27	34
Net actuarial (gain) loss	695	695	1,029
Total	722	722	1,063
Total accumulated benefit obligation for defined benefit pension plans	4,024	4,024	3,910
Changes in Plan Assets and Benefit Obligations Recognized in AOCI and Regulatory Assets/Liabilities by Type (Details) [Abstract]
AOCI	270	270	352
Regulatory assets/liabilities	452	452	711
Total	722	722	1,063
Pension Plans Where the Projected or Accumulated Benefit Obligation Exceed the Fair Value of Plan Assets (Details) [Abstract]
Projected benefit obligations	1,875	1,875	3,861
Fair value of plan assets where the projected benefit obligations exceed the value of plan assets	1,668	1,668	3,275
Accumulated benefit obligation	184	184	3,624
Fair value of plan assets where the accumulated benefit obligations exceed the value of plan assets	$ 0	$ 0	$ 3,275
Pension Plan [Member] | U.K. [Member]
Weighted Average Assumptions Used in the Valuation of the Benefit Obligations (Details) [Abstract]
Benefit obligations valuation discount rate	1.53%	1.53%	1.94%
Benefit obligations valuation rate of compensation increase	3.25%	3.25%	3.25%
Weighted Average Assumptions Used to Determine the Net Periodic Benefit Costs (Details) [Abstract]
Net periodic benefit costs discount rate - service cost		2.03%	3.12%	2.73%
Net periodic benefit costs discount rate - interest cost		1.73%	2.62%	2.31%
Net periodic benefit costs rate of compensation increase		3.25%	3.50%	3.50%
Net periodic benefit costs expected return on plan assets		7.13%	7.21%	7.23%
Change in Benefit Obligation [Roll Forward]
Benefit Obligation, beginning of period		$ 8,515	$ 7,275
Service cost		89	68	$ 82
Interest cost		143	187	185
Participant contributions		12	12
Plan Amendments		0	0
Actuarial (gain) loss		624	1,220
Settlements		0	0
Gross benefits paid		(366)	(363)
Federal subsidy		0	0
Currency conversion		281	116
Benefit Obligation, end of period	$ 9,298	9,298	8,515	7,275
Change in Plan Assets [Roll Forward]
Balance at beginning of period		8,945	7,801
Actual return on plan assets		805	1,095
Employer contributions		272	278
Participant contributions		12	12
Settlements		0	0
Gross benefits paid		(366)	(363)
Currency conversion		302	122
Balance at end of period	9,970	9,970	8,945	$ 7,801
Funded Status, end of period	672	672	430
Amounts recognized in the Balance Sheets consist of: [Abstract]
Noncurrent asset	682	682	440
Current liability	0	0	(1)
Noncurrent liability	(10)	(10)	(9)
Net amount recognized, end of period	672	672	430
Amounts recognized in AOCI and regulatory assets/liabilities (pre-tax): [Abstract]
Prior service cost (credit)	11	11	11
Net actuarial (gain) loss	3,682	3,682	3,435
Total	3,693	3,693	3,446
Total accumulated benefit obligation for defined benefit pension plans	8,516	8,516	7,821
Changes in Plan Assets and Benefit Obligations Recognized in AOCI and Regulatory Assets/Liabilities by Type (Details) [Abstract]
Total	3,693	3,693	3,446
Pension Plans Where the Projected or Accumulated Benefit Obligation Exceed the Fair Value of Plan Assets (Details) [Abstract]
Projected benefit obligations	11	11	10
Fair value of plan assets where the projected benefit obligations exceed the value of plan assets	0	0	0
Accumulated benefit obligation	11	11	10
Fair value of plan assets where the accumulated benefit obligations exceed the value of plan assets	$ 0	$ 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	2.84%	2.84%	3.60%
Benefit obligations valuation rate of compensation increase	3.75%	3.75%	3.76%
Weighted Average Assumptions Used to Determine the Net Periodic Benefit Costs (Details) [Abstract]
Net periodic benefit costs discount rate - service cost		3.60%	4.31%	3.64%
Net periodic benefit costs discount rate - interest cost		3.60%	4.31%	3.64%
Net periodic benefit costs rate of compensation increase		3.76%	3.76%	3.75%
Net periodic benefit costs expected return on plan assets		6.44%	6.46%	6.40%
Change in Benefit Obligation [Roll Forward]
Benefit Obligation, beginning of period		$ 557	$ 538
Service cost		6	6	$ 7
Interest cost		19	22	21
Participant contributions		15	14
Plan Amendments		5	0
Actuarial (gain) loss		29	34
Settlements		0	0
Gross benefits paid		(58)	(58)
Federal subsidy		0	1
Currency conversion		0	0
Benefit Obligation, end of period	$ 573	573	557	538
Change in Plan Assets [Roll Forward]
Balance at beginning of period		340	301
Actual return on plan assets		56	71
Employer contributions		18	10
Participant contributions		11	10
Settlements		0	0
Gross benefits paid		(58)	(52)
Currency conversion		0	0
Balance at end of period	367	367	340	$ 301
Funded Status, end of period	(206)	(206)	(217)
Amounts recognized in the Balance Sheets consist of: [Abstract]
Noncurrent asset	0	0	11
Current liability	(22)	(22)	(2)
Noncurrent liability	(184)	(184)	(226)
Net amount recognized, end of period	(206)	(206)	(217)
Amounts recognized in AOCI and regulatory assets/liabilities (pre-tax): [Abstract]
Prior service cost (credit)	14	14	10
Net actuarial (gain) loss	0	0	6
Total	14	14	16
Changes in Plan Assets and Benefit Obligations Recognized in AOCI and Regulatory Assets/Liabilities by Type (Details) [Abstract]
AOCI	10	10	13
Regulatory assets/liabilities	4	4	3
Total	14	14	16
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	(4)	(4)	179
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	$ 99	$ 99	$ 122
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	2.91%	2.91%	3.62%
Benefit obligations valuation rate of compensation increase	3.50%	3.50%	3.50%
Weighted Average Assumptions Used to Determine the Net Periodic Benefit Costs (Details) [Abstract]
Net periodic benefit costs discount rate		3.62%	4.35%	3.69%
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%	7.25%
Assumed Health Care Cost Trend Rates (Details) [Abstract]
Health care cost trend rate assumed for next year, obligations	6.50%	6.50%	6.60%	6.60%
Health care cost trend rate assumed for next year, cost	6.60%	6.60%	6.60%	6.60%
Rate to which the cost trend rate is assumed to decline (the ultimate trend rate), obligations	5.00%	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%	5.00%
Year that the rate reaches the ultimate trend rate, obligations		2027	2024	2023
Year that the rate reaches the ultimate trend rate, cost		2024	2023	2022
Change in Benefit Obligation [Roll Forward]
Benefit Obligation, beginning of period		$ 1,684	$ 1,580
Service cost		24	22	$ 25
Interest cost		57	66	63
Participant contributions		0	0
Plan Amendments		2	2
Actuarial (gain) loss		164	166
Settlements		(83)	(16)
Gross benefits paid		(63)	(136)
Benefit Obligation, end of period	$ 1,785	1,785	1,684	1,580
Change in Plan Assets [Roll Forward]
Balance at beginning of period		1,470	1,294
Actual return on plan assets		294	304
Employer contributions	23	50	24
Participant contributions		0	0
Settlements		(83)	(16)
Gross benefits paid		(63)	(136)
Balance at end of period	1,668	1,668	1,470	$ 1,294
Funded Status, end of period	(117)	(117)	(214)
Amounts recognized in the Balance Sheets consist of: [Abstract]
Noncurrent asset	0	0	24
Current liability	(5)	(5)	(5)
Noncurrent liability	(112)	(112)	(233)
Net amount recognized, end of period	(117)	(117)	(214)
Amounts recognized in AOCI and regulatory assets/liabilities (pre-tax): [Abstract]
Prior service cost (credit)	23	23	30
Net actuarial (gain) loss	296	296	380
Total	319	319	410
Total accumulated benefit obligation for defined benefit pension plans	1,657	1,657	1,561
Changes in Plan Assets and Benefit Obligations Recognized in AOCI and Regulatory Assets/Liabilities by Type (Details) [Abstract]
AOCI	127	127	132
Regulatory assets/liabilities	192	192	278
Total	319	319	410
Pension Plans Where the Projected or Accumulated Benefit Obligation Exceed the Fair Value of Plan Assets (Details) [Abstract]
Projected benefit obligations	1,785	1,785	1,398
Fair value of plan assets where the projected benefit obligations exceed the value of plan assets	1,668	1,668	1,160
Accumulated benefit obligation	104	104	1,276
Fair value of plan assets where the accumulated benefit obligations exceed the value of plan assets	$ 0	$ 0	$ 1,160
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	2.85%	2.85%	3.59%
Benefit obligations valuation rate of compensation increase	3.50%	3.50%	3.50%
Weighted Average Assumptions Used to Determine the Net Periodic Benefit Costs (Details) [Abstract]
Net periodic benefit costs discount rate		3.59%	4.32%	3.65%
Net periodic benefit costs rate of compensation increase		3.50%	3.50%	3.50%
Net periodic benefit costs expected return on plan assets		7.02%	7.00%	7.15%
Change in Benefit Obligation [Roll Forward]
Benefit Obligation, beginning of period		$ 208	$ 205
Service cost		4	4	$ 4
Interest cost		7	8	8
Participant contributions		9	7
Plan Amendments		5	0
Actuarial (gain) loss		18	5
Settlements		0	0
Gross benefits paid		(22)	(21)
Benefit Obligation, end of period	$ 229	229	208	205
Change in Plan Assets [Roll Forward]
Balance at beginning of period		141	117
Actual return on plan assets		28	27
Employer contributions		4	11
Participant contributions		9	7
Settlements		0	0
Gross benefits paid		(22)	(21)
Balance at end of period	160	160	141	$ 117
Funded Status, end of period	(69)	(69)	(67)
Amounts recognized in the Balance Sheets consist of: [Abstract]
Noncurrent asset	0	0	11
Current liability	(2)	(2)	(2)
Noncurrent liability	(67)	(67)	(76)
Net amount recognized, end of period	(69)	(69)	(67)
Amounts recognized in AOCI and regulatory assets/liabilities (pre-tax): [Abstract]
Prior service cost (credit)	14	14	10
Net actuarial (gain) loss	(37)	(37)	(37)
Total	(23)	(23)	(27)
Changes in Plan Assets and Benefit Obligations Recognized in AOCI and Regulatory Assets/Liabilities by Type (Details) [Abstract]
AOCI	2	2	4
Regulatory assets/liabilities	(25)	(25)	(31)
Total	$ (23)	$ (23)	$ (27)
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	0.00%	0.00%	3.60%
Weighted Average Assumptions Used to Determine the Net Periodic Benefit Costs (Details) [Abstract]
Net periodic benefit costs discount rate		0.00%	4.33%	3.65%
Net periodic benefit costs expected return on plan assets		0.00%	7.25%	7.25%
Change in Benefit Obligation [Roll Forward]
Benefit Obligation, beginning of period		$ 286	$ 285
Service cost			1	$ 1
Interest cost			11	12
Actuarial (gain) loss			25
Gross benefits paid			(36)
Benefit Obligation, end of period			286	285
Change in Plan Assets [Roll Forward]
Balance at beginning of period		310	281
Actual return on plan assets			64
Employer contributions			1
Gross benefits paid			(36)
Balance at end of period			310	$ 281
Funded Status, end of period			24
Amounts recognized in the Balance Sheets consist of: [Abstract]
Noncurrent asset			24
Net amount recognized, end of period			24
Amounts recognized in AOCI and regulatory assets/liabilities (pre-tax): [Abstract]
Prior service cost (credit)			17
Net actuarial (gain) loss			79
Total			96
Total accumulated benefit obligation for defined benefit pension plans			286
Changes in Plan Assets and Benefit Obligations Recognized in AOCI and Regulatory Assets/Liabilities by Type (Details) [Abstract]
Total			96
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	$ (78)	(78)	(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	68	68	63
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	(62)	(62)	(31)
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	$ 16	$ 16