Financing Activities - Credit Arrangements (Details) £ in Millions, $ in Millions	1 Months Ended	6 Months Ended
	Aug. 31, 2017	Jun. 30, 2017 USD ($)	Jun. 30, 2017 GBP (£)	Dec. 31, 2016 USD ($)	Dec. 31, 2016 GBP (£)
UNITED KINGDOM
Line of Credit Facility [Line Items]
Capacity | £			£ 1,375
Borrowed | £			631		£ 339
Letters of Credit and Commercial Paper Issued | £			4		4
Unused Capacity		$ 956	741
UNITED KINGDOM | Uncommitted Credit Facilities [Member]
Line of Credit Facility [Line Items]
Capacity | £			90
Borrowed		$ 65	50	$ 75	60
Letters of Credit and Commercial Paper Issued | £			4		£ 4
Unused Capacity | £			£ 36
Interest rate on outstanding borrowing		1.07%	1.07%	1.26%	1.26%
WPD PLC [Member] | UNITED KINGDOM | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date		Jan. 13, 2022
Capacity | £			£ 210
Borrowed		$ 200	155	$ 200	£ 160
Letters of Credit and Commercial Paper Issued | £			0		£ 0
Unused Capacity | £			£ 56
Interest rate on outstanding borrowing		1.87%	1.87%	1.43%	1.43%
Borrowed | £			£ 154
WPD PLC [Member] | UNITED KINGDOM | Term Loan Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date		Dec. 28, 2017
Capacity | £			230
Borrowed		$ 297	230		£ 0
Letters of Credit and Commercial Paper Issued | £			0		0
Unused Capacity | £			£ 0
Interest rate on outstanding borrowing		1.50%	1.50%
WPD South West [Member] | UNITED KINGDOM | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date		Jul. 29, 2021
Capacity | £			£ 245
Borrowed		$ 103	80	$ 137	110
Letters of Credit and Commercial Paper Issued | £			0		£ 0
Unused Capacity | £			£ 165
Interest rate on outstanding borrowing		0.65%	0.65%	0.66%	0.66%
WPD East Midlands [Member] | UNITED KINGDOM | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date		Jul. 29, 2021
Capacity | £			£ 300
Borrowed		$ 150	116	$ 11	£ 9
Letters of Credit and Commercial Paper Issued | £			0		£ 0
Unused Capacity | £			£ 184
Interest rate on outstanding borrowing		0.65%	0.65%	0.66%	0.66%
WPD West Midlands [Member] | UNITED KINGDOM | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date		Jul. 29, 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		$ 1,400
Borrowed		0		$ 0
Letters of Credit and Commercial Paper Issued		441		37
Unused Capacity		$ 959
PPL Capital Funding [Member] | UNITED STATES | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date		Jan. 27, 2022
Capacity		$ 950
Borrowed		0		0
Letters of Credit and Commercial Paper Issued		424		20
Unused Capacity		$ 526
PPL Capital Funding [Member] | UNITED STATES | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date		Nov. 12, 2018
Capacity		$ 300
Borrowed		0		0
Letters of Credit and Commercial Paper Issued		0		0
Unused Capacity		$ 300
PPL Capital Funding [Member] | UNITED STATES | Bilateral Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date		Mar. 16, 2018
Capacity		$ 150
Borrowed		0		0
Letters of Credit and Commercial Paper Issued		17		17
Unused Capacity		$ 133
PPL Electric [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date		Jan. 27, 2022
Capacity		$ 650
Borrowed		0		0
Letters of Credit and Commercial Paper Issued		1		296
Unused Capacity		$ 649
LKE [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date		Oct. 31, 2018
Capacity		$ 75
Borrowed		0		0
Letters of Credit and Commercial Paper Issued		0		0
Unused Capacity		$ 75
LGE [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date		Jan. 31, 2022
Capacity		$ 500
Borrowed		0		0
Letters of Credit and Commercial Paper Issued		207		169
Unused Capacity		293
KU [Member]
Line of Credit Facility [Line Items]
Capacity		598
Borrowed		0		0
Letters of Credit and Commercial Paper Issued		249		214
Unused Capacity		$ 349
KU [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date		Jan. 31, 2022
Capacity		$ 400
Borrowed		0		0
Letters of Credit and Commercial Paper Issued		51		16
Unused Capacity		$ 349
KU [Member] | Letter Of Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date		Oct. 01, 2017
Capacity		$ 198
Borrowed		0		0
Letters of Credit and Commercial Paper Issued		198		198
Unused Capacity		$ 0
KU [Member] | Letter Of Credit Facility [Member] | Subsequent Event [Member]
Line of Credit Facility [Line Items]
Expiration Date	Oct. 01, 2020
PPL Electric Utilities Corp [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date		Jan. 27, 2022
Capacity		$ 650
Borrowed		0		0
Letters of Credit and Commercial Paper Issued		1		296
Unused Capacity		$ 649
LG And E And KU Energy LLC [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date		Oct. 31, 2018
Capacity		$ 75
Borrowed		0		0
Letters of Credit and Commercial Paper Issued		0		0
Unused Capacity		$ 75
LG And E And KU Energy LLC [Member] | LGE [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date		Jan. 31, 2022
Capacity		$ 500
Borrowed		0		0
Letters of Credit and Commercial Paper Issued		207		169
Unused Capacity		293
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		249		214
Unused Capacity		$ 349
LG And E And KU Energy LLC [Member] | KU [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date		Jan. 31, 2022
Capacity		$ 400
Borrowed		0		0
Letters of Credit and Commercial Paper Issued		51		16
Unused Capacity		$ 349
LG And E And KU Energy LLC [Member] | KU [Member] | Letter Of Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date		Oct. 01, 2017
Capacity		$ 198
Borrowed		0		0
Letters of Credit and Commercial Paper Issued		198		198
Unused Capacity		$ 0
LG And E And KU Energy LLC [Member] | KU [Member] | Letter Of Credit Facility [Member] | Subsequent Event [Member]
Line of Credit Facility [Line Items]
Expiration Date	Oct. 01, 2020
Louisville Gas And Electric Co [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date		Jan. 31, 2022
Capacity		$ 500
Borrowed		0		0
Letters of Credit and Commercial Paper Issued		207		169
Unused Capacity		293
Kentucky Utilities Co [Member]
Line of Credit Facility [Line Items]
Capacity		598
Borrowed		0		0
Letters of Credit and Commercial Paper Issued		249		214
Unused Capacity		$ 349
Kentucky Utilities Co [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date		Jan. 31, 2022
Capacity		$ 400
Borrowed		0		0
Letters of Credit and Commercial Paper Issued		51		16
Unused Capacity		$ 349
Kentucky Utilities Co [Member] | Letter Of Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date		Oct. 01, 2017
Capacity		$ 198
Borrowed		0		0
Letters of Credit and Commercial Paper Issued		198		$ 198
Unused Capacity		$ 0
Kentucky Utilities Co [Member] | Letter Of Credit Facility [Member] | Subsequent Event [Member]
Line of Credit Facility [Line Items]
Expiration Date	Oct. 01, 2020