Financing Activities - Credit Arrangements (Details) £ in Millions, $ in Millions		9 Months Ended
		Sep. 30, 2016 USD ($)	Sep. 30, 2016 GBP (£)	Dec. 31, 2015 USD ($)	Dec. 31, 2015 GBP (£)
WPD PLC [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration date		Jan. 13, 2021
Interest rate on outstanding borrowing		1.35%	1.35%	1.83%	1.83%
WPD South West [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration date		Jul. 29, 2021
Interest rate on outstanding borrowing		0.68%	0.68%
WPD East Midlands [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration date		Jul. 29, 2021
Interest rate on outstanding borrowing		0.66%	0.66%
WPD West Midlands [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration date		Jul. 29, 2021
WPD [Member]
Line of Credit Facility [Line Items]
Unused capacity		$ 1,100
PPL Capital Funding [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration date		Jan. 29, 2021
PPL Capital Funding [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration date		Nov. 12, 2018
PPL Capital Funding [Member] | Bilateral Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration date		Mar. 17, 2017
PPL Electric [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration date		Jan. 29, 2021
LKE [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration date		Oct. 31, 2018
Interest rate on outstanding borrowing				1.68%	1.68%
LGE [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration date		Dec. 31, 2020
KU [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration date		Dec. 31, 2020
KU [Member] | Letter Of Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration date		Oct. 01, 2017
United Kingdom, Pounds [Member]
Line of Credit Facility [Line Items]
Capacity | £	[1]		£ 1,095
Borrowed | £	[1]		284		£ 133
Letters of credit and commercial paper issued | £	[1]		4		4
Unused capacity | £	[1]		807
United Kingdom, Pounds [Member] | WPD PLC [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Capacity | £			210
Borrowed		$ 200	153	$ 200	133
Unused capacity | £			57
United Kingdom, Pounds [Member] | WPD South West [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Capacity | £			245
Borrowed		131	100
Unused capacity | £			145
United Kingdom, Pounds [Member] | WPD East Midlands [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Capacity | £			300
Borrowed		40	31
Unused capacity | £			269
United Kingdom, Pounds [Member] | WPD West Midlands [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Capacity | £			300
Unused capacity | £			300
United Kingdom, Pounds [Member] | WPD [Member] | Uncommitted Credit Facilities [Member]
Line of Credit Facility [Line Items]
Capacity | £			40
Letters of credit and commercial paper issued | £			4		£ 4
Unused capacity | £			£ 36
United States of America, Dollars [Member] | PPL Capital Funding [Member]
Line of Credit Facility [Line Items]
Capacity		1,150
Letters of credit and commercial paper issued		17		471
Unused capacity		1,133
United States of America, Dollars [Member] | PPL Capital Funding [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Capacity		700
Letters of credit and commercial paper issued		0		151
Unused capacity		700
United States of America, Dollars [Member] | PPL Capital Funding [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Capacity		300
Letters of credit and commercial paper issued				300
Unused capacity		300
United States of America, Dollars [Member] | PPL Capital Funding [Member] | Bilateral Credit Facility [Member]
Line of Credit Facility [Line Items]
Capacity		150
Letters of credit and commercial paper issued		17		20
Unused capacity		133
United States of America, Dollars [Member] | PPL Electric [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Capacity		400
Letters of credit and commercial paper issued		131		1
Unused capacity		269
United States of America, Dollars [Member] | LKE [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Capacity		75
Borrowed	[2]			75
Unused capacity		75
United States of America, Dollars [Member] | LGE [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Capacity		500
Letters of credit and commercial paper issued		128		142
Unused capacity		372
United States of America, Dollars [Member] | KU [Member]
Line of Credit Facility [Line Items]
Capacity		598
Letters of credit and commercial paper issued		205		246
Unused capacity		393
United States of America, Dollars [Member] | KU [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Capacity		400
Letters of credit and commercial paper issued		7		48
Unused capacity		393
United States of America, Dollars [Member] | KU [Member] | Letter Of Credit Facility [Member]
Line of Credit Facility [Line Items]
Capacity		198
Letters of credit and commercial paper issued		$ 198		198
PPL Electric Utilities Corp [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration date		Jan. 29, 2021
PPL Electric Utilities Corp [Member] | United States of America, Dollars [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Capacity		$ 400
Letters of credit and commercial paper issued		131		$ 1
Unused capacity		$ 269
LG And E And KU Energy LLC [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration date	[2]	Oct. 31, 2018
Interest rate on outstanding borrowing				1.68%	1.68%
LG And E And KU Energy LLC [Member] | LGE [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration date		Dec. 31, 2020
LG And E And KU Energy LLC [Member] | KU [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration date		Dec. 31, 2020
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
LG And E And KU Energy LLC [Member] | United States of America, Dollars [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Borrowed	[2]			$ 75
Unused capacity	[2]	$ 75
LG And E And KU Energy LLC [Member] | United States of America, Dollars [Member] | LGE [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Letters of credit and commercial paper issued				142
Unused capacity		372
LG And E And KU Energy LLC [Member] | United States of America, Dollars [Member] | KU [Member]
Line of Credit Facility [Line Items]
Capacity		598
Letters of credit and commercial paper issued		205		246
Unused capacity		393
LG And E And KU Energy LLC [Member] | United States of America, Dollars [Member] | KU [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Letters of credit and commercial paper issued				48
Unused capacity		$ 393
LG And E And KU Energy LLC [Member] | United States of America, Dollars [Member] | KU [Member] | Letter Of Credit Facility [Member]
Line of Credit Facility [Line Items]
Letters of credit and commercial paper issued				198
Louisville Gas And Electric Co [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration date		Dec. 31, 2020
Louisville Gas And Electric Co [Member] | United States of America, Dollars [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Capacity		$ 500
Letters of credit and commercial paper issued		128		142
Unused capacity		$ 372
Kentucky Utilities Co [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration date		Dec. 31, 2020
Kentucky Utilities Co [Member] | Letter Of Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration date		Oct. 01, 2017
Kentucky Utilities Co [Member] | United States of America, Dollars [Member]
Line of Credit Facility [Line Items]
Capacity		$ 598
Letters of credit and commercial paper issued		205		246
Unused capacity		393
Kentucky Utilities Co [Member] | United States of America, Dollars [Member] | Syndicated Credit Facility [Member]
Line of Credit Facility [Line Items]
Capacity		400
Letters of credit and commercial paper issued		7		48
Unused capacity		393
Kentucky Utilities Co [Member] | United States of America, Dollars [Member] | Letter Of Credit Facility [Member]
Line of Credit Facility [Line Items]
Capacity		198
Letters of credit and commercial paper issued		$ 198		$ 198

[1] WPD plc's amounts borrowed at September 30, 2016 and December 31, 2015 were USD-denominated borrowings of $200 million for both periods, which bore interest at 1.35% and 1.83%. The unused capacity reflects the amount borrowed in GBP of £153 million as of the date borrowed. WPD (South West) amount borrowed at September 30, 2016 was a GBP-denominated borrowing which equated to $131 million and bore interest at 0.68%. WPD (East Midlands) amount borrowed at September 30, 2016 was a GBP-denominated borrowing which equated to $40 million and bore interest at 0.66%. At September 30, 2016, the unused capacity under the U.K. credit facilities was approximately $1.1 billion.

[2] LKE's interest rate on outstanding borrowings at December 31, 2015 was 1.68%.