Financing Activities - Credit Arrangements (Details) £ in Millions, $ in Millions	Sep. 30, 2019 USD ($)	Sep. 30, 2019 GBP (£)	Dec. 31, 2018 USD ($)	Dec. 31, 2018 GBP (£)
UNITED KINGDOM
Line of Credit Facility [Line Items]
Capacity | £		£ 1,155
Borrowed | £		252		£ 195
Letters of Credit and Commercial Paper Issued | £		4		4
Unused Capacity	$ 1,100	900
UNITED KINGDOM | Uncommitted Credit Facilities [Member]
Line of Credit Facility [Line Items]
Capacity | £		100
Borrowed	$ 44	36		0
Letters of Credit and Commercial Paper Issued | £		4		4
Unused Capacity | £		£ 60
Interest rate on outstanding borrowing	1.59%	1.59%
WPD PLC [Member] | UNITED KINGDOM | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Capacity | £		£ 210
Borrowed	$ 200	165	$ 200	157
Letters of Credit and Commercial Paper Issued | £		0		£ 0
Unused Capacity | £		£ 46
Interest rate on outstanding borrowing	2.94%	2.94%	3.17%	3.17%
Borrowed | £		£ 164
WPD South West [Member] | UNITED KINGDOM | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
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]
Capacity | £		300
Borrowed		0	$ 48	38
Letters of Credit and Commercial Paper Issued | £		0		£ 0
Unused Capacity | £		300
Interest rate on outstanding borrowing			1.12%	1.12%
WPD West Midlands [Member] | UNITED KINGDOM | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Capacity | £		300
Borrowed	$ 62	51		£ 0
Letters of Credit and Commercial Paper Issued | £		0		£ 0
Unused Capacity | £		£ 249
Interest rate on outstanding borrowing	1.11%	1.11%
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	996		684
Unused Capacity	554
PPL Capital Funding [Member] | UNITED STATES | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Capacity	1,450
Borrowed	0		0
Letters of Credit and Commercial Paper Issued	981		669
Unused Capacity	469
PPL Capital Funding [Member] | UNITED STATES | Bilateral Credit Facility [Member]
Line of Credit Facility [Line Items]
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]
Capacity	650
Borrowed	0		0
Letters of Credit and Commercial Paper Issued	1		1
Unused Capacity	649
LGE [Member]
Line of Credit Facility [Line Items]
Capacity	500
Borrowed	0		200
Letters of Credit and Commercial Paper Issued	99		279
Unused Capacity	401
LGE [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Capacity	500
Borrowed	0		0
Letters of Credit and Commercial Paper Issued	99		279
Unused Capacity	401
LGE [Member] | Term Loan Facility [Member]
Line of Credit Facility [Line Items]
Capacity	0
Borrowed	0		200
Letters of Credit and Commercial Paper Issued	0		0
Unused Capacity	0
KU [Member]
Line of Credit Facility [Line Items]
Capacity	400
Borrowed	0		0
Letters of Credit and Commercial Paper Issued	2		433
Unused Capacity	398
KU [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Capacity	400
Borrowed	0		0
Letters of Credit and Commercial Paper Issued	2		235
Unused Capacity	398
KU [Member] | Letter Of Credit Facility [Member]
Line of Credit Facility [Line Items]
Capacity	0
Borrowed	0		0
Letters of Credit and Commercial Paper Issued	0		198
Unused Capacity	0
PPL Electric Utilities Corp [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Capacity	650
Borrowed	0		0
Letters of Credit and Commercial Paper Issued	1		1
Unused Capacity	649
LG And E And KU Energy LLC [Member] | LGE [Member]
Line of Credit Facility [Line Items]
Capacity	500
Borrowed	0		200
Letters of Credit and Commercial Paper Issued	99		279
Unused Capacity	401
LG And E And KU Energy LLC [Member] | LGE [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Capacity	500
Borrowed	0		0
Letters of Credit and Commercial Paper Issued	99		279
Unused Capacity	401
LG And E And KU Energy LLC [Member] | LGE [Member] | Term Loan Facility [Member]
Line of Credit Facility [Line Items]
Capacity	0
Borrowed	0		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	400
Borrowed	0		0
Letters of Credit and Commercial Paper Issued	2		433
Unused Capacity	398
LG And E And KU Energy LLC [Member] | KU [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Capacity	400
Borrowed	0		0
Letters of Credit and Commercial Paper Issued	2		235
Unused Capacity	398
LG And E And KU Energy LLC [Member] | KU [Member] | Letter Of Credit Facility [Member]
Line of Credit Facility [Line Items]
Capacity	0
Borrowed	0		0
Letters of Credit and Commercial Paper Issued	0		198
Unused Capacity	0
Louisville Gas And Electric Co [Member]
Line of Credit Facility [Line Items]
Capacity	500
Borrowed	0		200
Letters of Credit and Commercial Paper Issued	99		279
Unused Capacity	401
Louisville Gas And Electric Co [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Capacity	500
Borrowed	0		0
Letters of Credit and Commercial Paper Issued	99		279
Unused Capacity	401
Louisville Gas And Electric Co [Member] | Term Loan Facility [Member]
Line of Credit Facility [Line Items]
Capacity	0
Borrowed	0		200
Letters of Credit and Commercial Paper Issued	0		0
Unused Capacity	0
Kentucky Utilities Co [Member]
Line of Credit Facility [Line Items]
Capacity	400
Borrowed	0		0
Letters of Credit and Commercial Paper Issued	2		433
Unused Capacity	398
Kentucky Utilities Co [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Capacity	400
Borrowed	0		0
Letters of Credit and Commercial Paper Issued	2		235
Unused Capacity	398
Kentucky Utilities Co [Member] | Letter Of Credit Facility [Member]
Line of Credit Facility [Line Items]
Capacity	0
Borrowed	0		0
Letters of Credit and Commercial Paper Issued	0		$ 198
Unused Capacity	$ 0