Financing Activities - Credit Arrangements (Details) £ in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2019 USD ($)	Mar. 31, 2019 GBP (£)	Dec. 31, 2018 USD ($)	Dec. 31, 2018 GBP (£)
UNITED KINGDOM
Line of Credit Facility [Line Items]
Capacity | £		£ 1,155
Borrowed | £		250		£ 195
Letters of Credit and Commercial Paper Issued | £		4		4
Unused Capacity	$ 1,200	899
UNITED KINGDOM | Uncommitted Credit Facilities [Member]
Line of Credit Facility [Line Items]
Capacity | £		100
Borrowed | £		0		0
Letters of Credit and Commercial Paper Issued | £		4		4
Unused Capacity | £		96
WPD PLC [Member] | UNITED KINGDOM | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date	Jan. 31, 2023
Capacity | £		210
Borrowed	$ 200	151	$ 200	157
Letters of Credit and Commercial Paper Issued | £		0		£ 0
Unused Capacity | £		£ 57
Interest rate on outstanding borrowing	3.32%	3.32%	3.17%	3.17%
Borrowings | £		£ 153
WPD South West [Member] | UNITED KINGDOM | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date	Jul. 31, 2021
Capacity | £		245
Borrowed | £		0		£ 0
Letters of Credit and Commercial Paper Issued | £		0		0
Unused Capacity | £		245
WPD East Midlands [Member] | UNITED KINGDOM | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date	Jul. 31, 2021
Capacity | £		300
Borrowed	$ 131	99	$ 48	38
Letters of Credit and Commercial Paper Issued | £		0		£ 0
Unused Capacity | £		£ 201
Interest rate on outstanding borrowing	1.13%	1.13%	1.12%	1.12%
WPD West Midlands [Member] | UNITED KINGDOM | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date	Jul. 31, 2021
Capacity | £		£ 300
Borrowed | £		0		£ 0
Letters of Credit and Commercial Paper Issued | £		0		£ 0
Unused Capacity | £		£ 300
PPL Capital Funding [Member] | UNITED STATES
Line of Credit Facility [Line Items]
Capacity	$ 1,550
Borrowed	0		$ 0
Letters of Credit and Commercial Paper Issued	983		684
Unused Capacity	$ 567
PPL Capital Funding [Member] | UNITED STATES | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date	Jan. 31, 2024
Capacity	$ 1,450
Borrowed	0		0
Letters of Credit and Commercial Paper Issued	968		669
Unused Capacity	$ 482
PPL Capital Funding [Member] | UNITED STATES | Bilateral Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date	Mar. 31, 2020
Capacity	$ 100
Borrowed	0		0
Letters of Credit and Commercial Paper Issued	15		15
Unused Capacity	$ 85
PPL Electric [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date	Jan. 31, 2024
Capacity	$ 650
Borrowed	0		0
Letters of Credit and Commercial Paper Issued	61		1
Unused Capacity	589
LGE [Member]
Line of Credit Facility [Line Items]
Capacity	700
Borrowed	200		200
Letters of Credit and Commercial Paper Issued	269		279
Unused Capacity	$ 231
LGE [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date	Jan. 31, 2024
Capacity	$ 500
Borrowed	0		0
Letters of Credit and Commercial Paper Issued	269		279
Unused Capacity	$ 231
LGE [Member] | Term Loan Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date	Oct. 31, 2019
Capacity	$ 200
Borrowed	200		200
Letters of Credit and Commercial Paper Issued	0		0
Unused Capacity	0
KU [Member]
Line of Credit Facility [Line Items]
Capacity	598
Borrowed	0		0
Letters of Credit and Commercial Paper Issued	431		433
Unused Capacity	$ 167
KU [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date	Jan. 31, 2024
Capacity	$ 400
Borrowed	0		0
Letters of Credit and Commercial Paper Issued	233		235
Unused Capacity	$ 167
KU [Member] | Letter Of Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date	Oct. 31, 2020
Capacity	$ 198
Borrowed	0		0
Letters of Credit and Commercial Paper Issued	198		198
Unused Capacity	$ 0
PPL Electric Utilities Corp [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date	Jan. 31, 2024
Capacity	$ 650
Borrowed	0		0
Letters of Credit and Commercial Paper Issued	61		1
Unused Capacity	589
LG And E And KU Energy LLC [Member] | LGE [Member]
Line of Credit Facility [Line Items]
Capacity	700
Borrowed	200		200
Letters of Credit and Commercial Paper Issued	269		279
Unused Capacity	$ 231
LG And E And KU Energy LLC [Member] | LGE [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date	Jan. 31, 2024
Capacity	$ 500
Borrowed	0		0
Letters of Credit and Commercial Paper Issued	269		279
Unused Capacity	$ 231
LG And E And KU Energy LLC [Member] | LGE [Member] | Term Loan Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date	Oct. 31, 2019
Capacity	$ 200
Borrowed	200		200
Letters of Credit and Commercial Paper Issued	0		0
Unused Capacity	0
LG And E And KU Energy LLC [Member] | KU [Member]
Line of Credit Facility [Line Items]
Capacity	598
Borrowed	0		0
Letters of Credit and Commercial Paper Issued	431		433
Unused Capacity	$ 167
LG And E And KU Energy LLC [Member] | KU [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date	Jan. 31, 2024
Capacity	$ 400
Borrowed	0		0
Letters of Credit and Commercial Paper Issued	233		235
Unused Capacity	$ 167
LG And E And KU Energy LLC [Member] | KU [Member] | Letter Of Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date	Oct. 31, 2020
Capacity	$ 198
Borrowed	0		0
Letters of Credit and Commercial Paper Issued	198		198
Unused Capacity	0
Louisville Gas And Electric Co [Member]
Line of Credit Facility [Line Items]
Capacity	700
Borrowed	200		200
Letters of Credit and Commercial Paper Issued	269		279
Unused Capacity	$ 231
Louisville Gas And Electric Co [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date	Jan. 31, 2024
Capacity	$ 500
Borrowed	0		0
Letters of Credit and Commercial Paper Issued	269		279
Unused Capacity	$ 231
Louisville Gas And Electric Co [Member] | Term Loan Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date	Oct. 31, 2019
Capacity	$ 200
Borrowed	200		200
Letters of Credit and Commercial Paper Issued	0		0
Unused Capacity	0
Kentucky Utilities Co [Member]
Line of Credit Facility [Line Items]
Capacity	598
Borrowed	0		0
Letters of Credit and Commercial Paper Issued	431		433
Unused Capacity	$ 167
Kentucky Utilities Co [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date	Jan. 31, 2024
Capacity	$ 400
Borrowed	0		0
Letters of Credit and Commercial Paper Issued	233		235
Unused Capacity	$ 167
Kentucky Utilities Co [Member] | Letter Of Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date	Oct. 31, 2020
Capacity	$ 198
Borrowed	0		0
Letters of Credit and Commercial Paper Issued	198		$ 198
Unused Capacity	$ 0