Defined Benefits (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Pension Plan [Member] | U.S.
Net Periodic Defined Benefit Costs (Credits) (Details) [Abstract]
Service cost	$ 13	$ 15	$ 38	$ 46
Interest cost	41	39	123	117
Expected return on plan assets	(62)	(62)	(184)	(186)
Amortization of: [Abstract]
Prior service cost	2	2	6	7
Actuarial loss	15	22	42	63
Net Periodic Defined Benefit Costs (Credits) Prior To Settlements	9	16	25	47
Settlements	0	0	1	0
Net periodic defined benefit costs (credits)	9	16	26	47
Pension Plan [Member] | U.K.
Net Periodic Defined Benefit Costs (Credits) (Details) [Abstract]
Service cost	17	21	51	63
Interest cost	45	46	140	140
Expected return on plan assets	(144)	(145)	(442)	(445)
Amortization of: [Abstract]
Prior service cost	1	0	1	0
Actuarial loss	22	37	69	114
Net Periodic Defined Benefit Costs (Credits) Prior To Settlements	(59)	(41)	(181)	(128)
Settlements	0	0	0	0
Net periodic defined benefit costs (credits)	(59)	(41)	(181)	(128)
Other Postretirement Benefits Plan [Member]
Net Periodic Defined Benefit Costs (Credits) (Details) [Abstract]
Service cost	2	1	4	5
Interest cost	5	5	16	15
Expected return on plan assets	(5)	(4)	(14)	(17)
Amortization of: [Abstract]
Actuarial loss	1	0	1	0
Net periodic defined benefit costs (credits)	3	2	7	3
PPL Electric Utilities Corp [Member] | PPL Services [Member]
Net Periodic Defined Benefit Costs Allocated to Subsidiary by Sponsor (Numeric) [Abstract]
Costs allocated to subsidiary by plan sponsors	3	5	8	12
LG And E And KU Energy LLC [Member] | Pension Plan [Member]
Net Periodic Defined Benefit Costs (Credits) (Details) [Abstract]
Service cost	5	6	16	18
Interest cost	16	16	49	48
Expected return on plan assets	(25)	(25)	(76)	(76)
Amortization of: [Abstract]
Prior service cost	2	3	6	7
Actuarial loss	7	8	17	26
Net periodic defined benefit costs (credits)	$ 5	$ 8	$ 12	$ 23
Regulatory Asset Amortization Period	15 years	15 years	15 years	15 years
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period	$ 2	$ 2	$ 3	$ 8
LG And E And KU Energy LLC [Member] | Other Postretirement Benefits Plan [Member]
Net Periodic Defined Benefit Costs (Credits) (Details) [Abstract]
Service cost	1	1	3	3
Interest cost	2	2	6	6
Expected return on plan assets	(2)	(2)	(6)	(6)
Amortization of: [Abstract]
Prior service cost	0	0	1	1
Actuarial loss	0	0	(1)	(1)
Net periodic defined benefit costs (credits)	1	1	3	3
Louisville Gas And Electric Co [Member] | LKE [Member]
Net Periodic Defined Benefit Costs Allocated to Subsidiary by Sponsor (Numeric) [Abstract]
Costs allocated to subsidiary by plan sponsors	1	1	3	5
Louisville Gas And Electric Co [Member] | Pension Plan [Member]
Net Periodic Defined Benefit Costs (Credits) (Details) [Abstract]
Service cost	0	0	1	1
Interest cost	2	3	8	9
Expected return on plan assets	(5)	(6)	(16)	(17)
Amortization of: [Abstract]
Prior service cost	1	1	4	4
Actuarial loss	4	2	7	5
Net periodic defined benefit costs (credits)	$ 2	$ 0	$ 4	$ 2
Regulatory Asset Amortization Period	15 years	15 years	15 years	15 years
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period	$ 1		$ 2	$ 1
Louisville Gas And Electric Co [Member] | Qualified Plan [Member] | Pension Plan [Member] | U.S.
Amortization of: [Abstract]
Settlements	5	$ 1	5	5
Kentucky Utilities Co [Member] | LKE [Member]
Net Periodic Defined Benefit Costs Allocated to Subsidiary by Sponsor (Numeric) [Abstract]
Costs allocated to subsidiary by plan sponsors	$ 0	$ 1	$ 0	$ 3