Fair Value Measurements - Financial Instruments Not Recorded at Fair Value (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Carrying Amount [Member]
Fair Value of Financial Instruments Not Recorded at Fair Value - Other
Debt Instrument, Fair Value Disclosure	$ 21,840	$ 21,893
Fair Value [Member]
Fair Value of Financial Instruments Not Recorded at Fair Value - Other
Debt Instrument, Fair Value Disclosure	25,175	25,481
PPL Electric Utilities Corp [Member] | Carrying Amount [Member]
Fair Value of Financial Instruments Not Recorded at Fair Value - Other
Debt Instrument, Fair Value Disclosure	3,986	3,985
PPL Electric Utilities Corp [Member] | Fair Value [Member]
Fair Value of Financial Instruments Not Recorded at Fair Value - Other
Debt Instrument, Fair Value Disclosure	4,500	4,589
LG And E And KU Energy LLC [Member] | Carrying Amount [Member]
Fair Value of Financial Instruments Not Recorded at Fair Value - Other
Debt Instrument, Fair Value Disclosure	6,003	6,002
LG And E And KU Energy LLC [Member] | Fair Value [Member]
Fair Value of Financial Instruments Not Recorded at Fair Value - Other
Debt Instrument, Fair Value Disclosure	6,774	6,766
Louisville Gas And Electric Co [Member] | Carrying Amount [Member]
Fair Value of Financial Instruments Not Recorded at Fair Value - Other
Debt Instrument, Fair Value Disclosure	2,005	2,005
Louisville Gas And Electric Co [Member] | Fair Value [Member]
Fair Value of Financial Instruments Not Recorded at Fair Value - Other
Debt Instrument, Fair Value Disclosure	2,254	2,278
Kentucky Utilities Co [Member] | Carrying Amount [Member]
Fair Value of Financial Instruments Not Recorded at Fair Value - Other
Debt Instrument, Fair Value Disclosure	2,624	2,623
Kentucky Utilities Co [Member] | Fair Value [Member]
Fair Value of Financial Instruments Not Recorded at Fair Value - Other
Debt Instrument, Fair Value Disclosure	$ 2,978	$ 3,003