Fair Value Measurements - Financial Instruments Not Recorded at Fair Value (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Carrying Amount [Member]
Fair Value of Financial Instruments Not Recorded at Fair Value - Other
Debt Instrument, Fair Value Disclosure	$ 14,691	$ 14,689
Fair Value [Member]
Fair Value of Financial Instruments Not Recorded at Fair Value - Other
Debt Instrument, Fair Value Disclosure	16,607	17,774
PPL Electric Utilities Corp [Member] | Carrying Amount [Member]
Fair Value of Financial Instruments Not Recorded at Fair Value - Other
Debt Instrument, Fair Value Disclosure	4,237	4,236
PPL Electric Utilities Corp [Member] | Fair Value [Member]
Fair Value of Financial Instruments Not Recorded at Fair Value - Other
Debt Instrument, Fair Value Disclosure	4,881	5,338
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	6,075	6,074
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	7,051	7,589
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	2,007	2,007
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	2,321	2,499
Kentucky Utilities Co [Member] | Carrying Amount [Member]
Fair Value of Financial Instruments Not Recorded at Fair Value - Other
Debt Instrument, Fair Value Disclosure	2,618	2,618
Kentucky Utilities Co [Member] | Fair Value [Member]
Fair Value of Financial Instruments Not Recorded at Fair Value - Other
Debt Instrument, Fair Value Disclosure	$ 3,042	$ 3,334