Financing Activities - Credit Arrangements (Details) £ in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2017 USD ($)	Mar. 31, 2017 GBP (£)	Feb. 28, 2017 GBP (£)	Dec. 31, 2016 USD ($)	Dec. 31, 2016 GBP (£)
UNITED KINGDOM
Line of Credit Facility [Line Items]
Capacity | £		£ 1,375
Borrowed | £		591			£ 339
Letters of Credit and Commercial Paper Issued | £		4			4
Unused Capacity	$ 972	780
UNITED KINGDOM | Uncommitted Credit Facilities [Member]
Line of Credit Facility [Line Items]
Capacity | £		90
Borrowed		0		$ 75	60
Letters of Credit and Commercial Paper Issued | £		4			£ 4
Unused Capacity | £		86
Interest rate on outstanding borrowing				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	161	£ 161	$ 200	£ 160
Letters of Credit and Commercial Paper Issued | £		0			£ 0
Unused Capacity | £		£ 49
Interest rate on outstanding borrowing	1.61%	1.61%		1.43%	1.43%
WPD PLC [Member] | UNITED KINGDOM | Term Loan Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date	Dec. 28, 2017
Capacity | £		£ 230
Borrowed	$ 286	230			£ 0
Letters of Credit and Commercial Paper Issued | £		0			0
Unused Capacity | £		£ 0
Interest rate on outstanding borrowing	1.51%	1.51%
WPD South West [Member] | UNITED KINGDOM | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date	Jul. 29, 2021
Capacity | £		£ 245
Borrowed	$ 90	72		$ 137	110
Letters of Credit and Commercial Paper Issued | £		0			£ 0
Unused Capacity | £		£ 173
Interest rate on outstanding borrowing	0.66%	0.66%		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	$ 159	128		$ 11	£ 9
Letters of Credit and Commercial Paper Issued | £		0			£ 0
Unused Capacity | £		£ 172
Interest rate on outstanding borrowing	0.66%	0.66%		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	206			37
Unused Capacity	$ 1,194
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	189			20
Unused Capacity	$ 761
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	500			296
Unused Capacity	$ 150
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	234			214
Unused Capacity	$ 364
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	36			16
Unused Capacity	$ 364
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
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	500			296
Unused Capacity	$ 150
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	234			214
Unused Capacity	$ 364
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	36			16
Unused Capacity	$ 364
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
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	234			214
Unused Capacity	$ 364
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	36			16
Unused Capacity	$ 364
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