Leases - Lessor (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019 USD ($)
Lessor, Lease, Description [Line Items]
2019	$ 11
2020	13
2021	10
2022	4
2023	4
2024	4
Thereafter	12
Total	58
Operating Lease, Lease Income	$ 4
LKE [Member]
Lessor, Lease, Description [Line Items]
Lessor, Operating Lease, Expiration Date	Dec. 31, 2021
LGE [Member]
Lessor, Lease, Description [Line Items]
Lessor, Operating Lease, Expiration Date	Dec. 31, 2021
KU [Member]
Lessor, Lease, Description [Line Items]
Lessor, Operating Lease, Expiration Date	Dec. 31, 2021
WPD [Member]
Lessor, Lease, Description [Line Items]
Lessor, Operating Lease, Expiration Date	Dec. 31, 2029
LG And E And KU Energy LLC [Member]
Lessor, Lease, Description [Line Items]
Lessor, Operating Lease, Expiration Date	Dec. 31, 2021
2019	$ 6
2020	7
2021	5
2022	0
2023	1
2024	0
Thereafter	0
Total	19
Operating Lease, Lease Income	$ 2
Louisville Gas And Electric Co [Member]
Lessor, Lease, Description [Line Items]
Lessor, Operating Lease, Expiration Date	Dec. 31, 2021
Kentucky Utilities Co [Member]
Lessor, Lease, Description [Line Items]
Lessor, Operating Lease, Expiration Date	Dec. 31, 2021
2019	$ 6
2020	7
2021	5
2022	0
2023	0
2024	0
Thereafter	0
Total	18
Operating Lease, Lease Income	$ 2