Fair Value Measurements (Financial Instruments Not Recorded at Fair Value) (Details) - USD ($) $ in Millions		Mar. 31, 2016	Dec. 31, 2015
Carrying Amount [Member]
Fair Value of Financial Instruments Not Recorded at Fair Value - Other
Long-term debt	[1]	$ 18,559	$ 19,048
Fair Value [Member]
Fair Value of Financial Instruments Not Recorded at Fair Value - Other
Long-term debt		21,046	21,218
PPL Electric Utilities Corp [Member] | Carrying Amount [Member]
Fair Value of Financial Instruments Not Recorded at Fair Value - Other
Long-term debt	[1]	2,829	2,828
PPL Electric Utilities Corp [Member] | Fair Value [Member]
Fair Value of Financial Instruments Not Recorded at Fair Value - Other
Long-term debt		3,216	3,088
LG And E And KU Energy LLC [Member] | Carrying Amount [Member]
Fair Value of Financial Instruments Not Recorded at Fair Value - Other
Long-term debt	[1]	5,088	5,088
LG And E And KU Energy LLC [Member] | Fair Value [Member]
Fair Value of Financial Instruments Not Recorded at Fair Value - Other
Long-term debt		5,625	5,384
Louisville Gas And Electric Co [Member] | Carrying Amount [Member]
Fair Value of Financial Instruments Not Recorded at Fair Value - Other
Long-term debt	[1]	1,642	1,642
Louisville Gas And Electric Co [Member] | Fair Value [Member]
Fair Value of Financial Instruments Not Recorded at Fair Value - Other
Long-term debt		1,779	1,704
Kentucky Utilities Co [Member] | Carrying Amount [Member]
Fair Value of Financial Instruments Not Recorded at Fair Value - Other
Long-term debt	[1]	2,326	2,326
Kentucky Utilities Co [Member] | Fair Value [Member]
Fair Value of Financial Instruments Not Recorded at Fair Value - Other
Long-term debt		$ 2,587	$ 2,467

[1] A mount s are net of debt issuance costs.