Fair Value Measurements (Assets and Liabilities Measured on Recurring Basis Table) (Details) - Recurring [Member] - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Assets
Cash and cash equivalents	$ 708	$ 815
Restricted cash and cash equivalents	19	21
Commingled debt fund measured at NAV	26	29
Commingled equity fund measured at NAV	25	27
Total special use funds	51	56
Price risk management assets:
Foreign currency contracts	0	142
Cross-currency swaps	146	154
Total price risk management assets	146	296
Total Assets	924	1,188
Price risk management liabilities:
Interest rate swaps	23	21
Foreign currency contracts	137	5
Total price risk management liabilities	160	26
Level 1 [Member]
Assets
Cash and cash equivalents	708	815
Restricted cash and cash equivalents	19	21
Total special use funds	0	0
Price risk management assets:
Foreign currency contracts	0	0
Cross-currency swaps	0	0
Total price risk management assets	0	0
Total Assets	727	836
Price risk management liabilities:
Interest rate swaps	0	0
Foreign currency contracts	0	0
Total price risk management liabilities	0	0
Level 2 [Member]
Assets
Cash and cash equivalents	0	0
Restricted cash and cash equivalents	0	0
Total special use funds	0	0
Price risk management assets:
Foreign currency contracts	0	142
Cross-currency swaps	146	154
Total price risk management assets	146	296
Total Assets	146	296
Price risk management liabilities:
Interest rate swaps	23	21
Foreign currency contracts	137	5
Total price risk management liabilities	160	26
Level 3 [Member]
Assets
Cash and cash equivalents	0	0
Restricted cash and cash equivalents	0	0
Total special use funds	0	0
Price risk management assets:
Foreign currency contracts	0	0
Cross-currency swaps	0	0
Total price risk management assets	0	0
Total Assets	0	0
Price risk management liabilities:
Interest rate swaps	0	0
Foreign currency contracts	0	0
Total price risk management liabilities	0	0
PPL Electric Utilities Corp [Member]
Assets
Cash and cash equivalents	40	262
Restricted cash and cash equivalents	0	2
Price risk management assets:
Total Assets	40	264
PPL Electric Utilities Corp [Member] | Level 1 [Member]
Assets
Cash and cash equivalents	40	262
Restricted cash and cash equivalents	0	2
Price risk management assets:
Total Assets	40	264
PPL Electric Utilities Corp [Member] | Level 2 [Member]
Assets
Cash and cash equivalents	0	0
Restricted cash and cash equivalents	0	0
Price risk management assets:
Total Assets	0	0
PPL Electric Utilities Corp [Member] | Level 3 [Member]
Assets
Cash and cash equivalents	0	0
Restricted cash and cash equivalents	0	0
Price risk management assets:
Total Assets	0	0
LG And E And KU Energy LLC [Member]
Assets
Cash and cash equivalents	29	27
Price risk management assets:
Total Assets	29	27
Price risk management liabilities:
Interest rate swaps	23	21
Total price risk management liabilities	23	21
LG And E And KU Energy LLC [Member] | Level 1 [Member]
Assets
Cash and cash equivalents	29	27
Price risk management assets:
Total Assets	29	27
Price risk management liabilities:
Interest rate swaps	0	0
Total price risk management liabilities	0	0
LG And E And KU Energy LLC [Member] | Level 2 [Member]
Assets
Cash and cash equivalents	0	0
Price risk management assets:
Total Assets	0	0
Price risk management liabilities:
Interest rate swaps	23	21
Total price risk management liabilities	23	21
LG And E And KU Energy LLC [Member] | Level 3 [Member]
Assets
Cash and cash equivalents	0	0
Price risk management assets:
Total Assets	0	0
Price risk management liabilities:
Interest rate swaps	0	0
Total price risk management liabilities	0	0
Louisville Gas And Electric Co [Member]
Assets
Cash and cash equivalents	7	15
Price risk management assets:
Total Assets	7	15
Price risk management liabilities:
Interest rate swaps	23	21
Total price risk management liabilities	23	21
Louisville Gas And Electric Co [Member] | Level 1 [Member]
Assets
Cash and cash equivalents	7	15
Price risk management assets:
Total Assets	7	15
Price risk management liabilities:
Interest rate swaps	0	0
Total price risk management liabilities	0	0
Louisville Gas And Electric Co [Member] | Level 2 [Member]
Assets
Cash and cash equivalents	0	0
Price risk management assets:
Total Assets	0	0
Price risk management liabilities:
Interest rate swaps	23	21
Total price risk management liabilities	23	21
Louisville Gas And Electric Co [Member] | Level 3 [Member]
Assets
Cash and cash equivalents	0	0
Price risk management assets:
Total Assets	0	0
Price risk management liabilities:
Interest rate swaps	0	0
Total price risk management liabilities	0	0
Kentucky Utilities Co [Member]
Assets
Cash and cash equivalents	22	12
Price risk management assets:
Total Assets	22	12
Kentucky Utilities Co [Member] | Level 1 [Member]
Assets
Cash and cash equivalents	22	12
Price risk management assets:
Total Assets	22	12
Kentucky Utilities Co [Member] | Level 2 [Member]
Assets
Cash and cash equivalents	0	0
Price risk management assets:
Total Assets	0	0
Kentucky Utilities Co [Member] | Level 3 [Member]
Assets
Cash and cash equivalents	0	0
Price risk management assets:
Total Assets	$ 0	$ 0