Fair Value Measurements - Financial Instruments Not Recorded at Fair Value (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Carrying Amount [Member]
Fair Value of Financial Instruments Not Recorded at Fair Value - Other
Debt Instrument, Fair Value Disclosure	$ 11,139	$ 14,689
Fair Value [Member]
Fair Value of Financial Instruments Not Recorded at Fair Value - Other
Debt Instrument, Fair Value Disclosure	13,091	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	4,483	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	5,296	5,338
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	2,006	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	2,387	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	$ 3,157	$ 3,334