Revenue from Contracts with Customers (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Jun. 30, 2021	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of Revenue from Contracts with Customers [Abstract]
Operating Revenues	$ 1,885	$ 1,933	$ 5,678	$ 5,815
Alternative Revenue Programs	(1)	8	(12)	(18)
Other Revenue	(5)	(11)	(22)	(30)
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	1,879	1,930	5,644	5,767
Contract with Customer, Asset and Liability [Abstract]
Accounts Receivable, Credit Loss Expense (Reversal)	8	11	22	22
Contract with Customer, Liability	40	42	40	42		$ 44	$ 42
Contract with Customer, Liability, Revenue Recognized			28	31
Licensed energy suppliers [Member]
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	440	454	1,472	1,520
Residential [Member]
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	651	708	1,948	2,058
Commercial [Member]
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	310	346	896	967
Industrial [Member]
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	156	164	434	470
Other [Member]
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	130	128	354	360
Wholesale - municipal [Member]
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	7	6	15	38
Wholesale - other [Member]
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	11	12	28	36
Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	174	112	497	318
Pennsylvania Regulated [Member]
Reconciliation of Revenue from Contracts with Customers [Abstract]
Operating Revenues	586	590	1,748	1,756
United Kingdom Regulated [Member]
Reconciliation of Revenue from Contracts with Customers [Abstract]
Operating Revenues	485	491	1,575	1,615
Kentucky Regulated [Member]
Reconciliation of Revenue from Contracts with Customers [Abstract]
Operating Revenues	806	844	2,331	2,421
Corporate and Other [Member]
Reconciliation of Revenue from Contracts with Customers [Abstract]
Operating Revenues	8	8	24	23
Corporate and Other [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-06-30
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	40		40
Corporate and Other [Member] | Forecast [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-06-30
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount					$ 40
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period					12 months
PPL Electric Utilities Corp [Member]
Reconciliation of Revenue from Contracts with Customers [Abstract]
Operating Revenues	586	590	1,748	1,756
Alternative Revenue Programs	(5)	2	(6)	(4)
Other Revenue	0	(3)	(3)	(8)
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	581	589	1,739	1,744
Contract with Customer, Asset and Liability [Abstract]
Accounts Receivable, Credit Loss Expense (Reversal)	3	8	12	14
Contract with Customer, Liability	18	19	18	19		21	23
Contract with Customer, Liability, Revenue Recognized			9	11
PPL Electric Utilities Corp [Member] | Licensed energy suppliers [Member]
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	0	0	0	0
PPL Electric Utilities Corp [Member] | Residential [Member]
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	303	352	937	1,060
PPL Electric Utilities Corp [Member] | Commercial [Member]
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	79	97	234	279
PPL Electric Utilities Corp [Member] | Industrial [Member]
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	13	16	33	48
PPL Electric Utilities Corp [Member] | Other [Member]
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	12	12	38	39
PPL Electric Utilities Corp [Member] | Wholesale - municipal [Member]
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	0	0	0	0
PPL Electric Utilities Corp [Member] | Wholesale - other [Member]
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	0	0	0	0
PPL Electric Utilities Corp [Member] | Distribution [Member]
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	407	477	1,200	1,400
PPL Electric Utilities Corp [Member] | Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	174	112	497	318
LG And E And KU Energy LLC [Member]
Reconciliation of Revenue from Contracts with Customers [Abstract]
Operating Revenues	806	844	2,331	2,421
Alternative Revenue Programs	4	6	(6)	(14)
Other Revenue	(4)	(6)	(14)	(16)
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	806	844	2,311	2,391
Contract with Customer, Asset and Liability [Abstract]
Accounts Receivable, Credit Loss Expense (Reversal)	4	2	7	5
Contract with Customer, Liability	9	9	9	9		9	9
Contract with Customer, Liability, Revenue Recognized			9	9
LG And E And KU Energy LLC [Member] | Licensed energy suppliers [Member]
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	0	0	0	0
LG And E And KU Energy LLC [Member] | Residential [Member]
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	348	356	1,011	998
LG And E And KU Energy LLC [Member] | Commercial [Member]
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	231	249	662	688
LG And E And KU Energy LLC [Member] | Industrial [Member]
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	143	148	401	422
LG And E And KU Energy LLC [Member] | Other [Member]
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	66	73	194	209
LG And E And KU Energy LLC [Member] | Wholesale - municipal [Member]
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	7	6	15	38
LG And E And KU Energy LLC [Member] | Wholesale - other [Member]
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	11	12	28	36
LG And E And KU Energy LLC [Member] | Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	0	0	0	0
Louisville Gas And Electric Co [Member]
Reconciliation of Revenue from Contracts with Customers [Abstract]
Operating Revenues	363	382	1,092	1,126
Alternative Revenue Programs	2	4	(2)	(1)
Other Revenue	(2)	(3)	(6)	(7)
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	363	383	1,084	1,118
Contract with Customer, Asset and Liability [Abstract]
Accounts Receivable, Credit Loss Expense (Reversal)	3	1	4	2
Contract with Customer, Liability	5	5	5	5		5	5
Contract with Customer, Liability, Revenue Recognized			5	5
Louisville Gas And Electric Co [Member] | Licensed energy suppliers [Member]
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	0	0	0	0
Louisville Gas And Electric Co [Member] | Residential [Member]
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	173	177	509	504
Louisville Gas And Electric Co [Member] | Commercial [Member]
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	112	123	336	352
Louisville Gas And Electric Co [Member] | Industrial [Member]
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	47	47	130	134
Louisville Gas And Electric Co [Member] | Other [Member]
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	28	31	84	93
Louisville Gas And Electric Co [Member] | Wholesale - municipal [Member]
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	0	0	0	0
Louisville Gas And Electric Co [Member] | Wholesale - other [Member]
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	3	5	25	35
Louisville Gas And Electric Co [Member] | Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	0	0	0	0
Kentucky Utilities Co [Member]
Reconciliation of Revenue from Contracts with Customers [Abstract]
Operating Revenues	452	466	1,272	1,322
Alternative Revenue Programs	2	2	(4)	(13)
Other Revenue	(2)	(3)	(8)	(9)
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	452	465	1,260	1,300
Contract with Customer, Asset and Liability [Abstract]
Accounts Receivable, Credit Loss Expense (Reversal)	1	1	3	3
Contract with Customer, Liability	4	4	4	4		$ 4	$ 4
Contract with Customer, Liability, Revenue Recognized			4	4
Kentucky Utilities Co [Member] | Licensed energy suppliers [Member]
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	0	0	0	0
Kentucky Utilities Co [Member] | Residential [Member]
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	175	179	502	494
Kentucky Utilities Co [Member] | Commercial [Member]
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	119	126	326	336
Kentucky Utilities Co [Member] | Industrial [Member]
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	96	101	271	288
Kentucky Utilities Co [Member] | Other [Member]
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	38	42	110	116
Kentucky Utilities Co [Member] | Wholesale - municipal [Member]
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	7	6	15	38
Kentucky Utilities Co [Member] | Wholesale - other [Member]
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	17	11	36	28
Kentucky Utilities Co [Member] | Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenues from Contracts with Customers	$ 0	$ 0	$ 0	$ 0