Fair Value Measurements - Assets and Liabilities Measured on Recurring Basis Table (Details) - Recurring Fair Value Measurements [Member] - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Assets
Cash and cash equivalents	$ 1,278	$ 815
Restricted cash and cash equivalents	23	21
Special Use Funds [Abstract]
Commingled debt fund measured at NAV	27	29
Commingled equity fund measured at NAV	26	27
Total special use funds	53	56
Price risk management assets:
Foreign currency contracts	108	142
Cross-currency swaps	201	154
Total price risk management assets	309	296
Total Assets	1,663	1,188
Price risk management liabilities:
Interest rate swaps	38	21
Foreign currency contracts	0	5
Total price risk management liabilities	38	26
Level 1 [Member]
Assets
Cash and cash equivalents	1,278	815
Restricted cash and cash equivalents	23	21
Special Use Funds [Abstract]
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	1,301	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
Special Use Funds [Abstract]
Total special use funds	0	0
Price risk management assets:
Foreign currency contracts	108	142
Cross-currency swaps	201	154
Total price risk management assets	309	296
Total Assets	309	296
Price risk management liabilities:
Interest rate swaps	38	21
Foreign currency contracts	0	5
Total price risk management liabilities	38	26
Level 3 [Member]
Assets
Cash and cash equivalents	0	0
Restricted cash and cash equivalents	0	0
Special Use Funds [Abstract]
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	13	262
Restricted cash and cash equivalents	2	2
Price risk management assets:
Total Assets	15	264
PPL Electric Utilities Corp [Member] | Level 1 [Member]
Assets
Cash and cash equivalents	13	262
Restricted cash and cash equivalents	2	2
Price risk management assets:
Total Assets	15	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	152	27
Cash collateral posted to counterparties	2	0
Price risk management assets:
Total Assets	154	27
Price risk management liabilities:
Interest rate swaps	28	21
Total price risk management liabilities	28	21
LG And E And KU Energy LLC [Member] | Level 1 [Member]
Assets
Cash and cash equivalents	152	27
Cash collateral posted to counterparties	2	0
Price risk management assets:
Total Assets	154	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
Cash collateral posted to counterparties	0	0
Price risk management assets:
Total Assets	0	0
Price risk management liabilities:
Interest rate swaps	28	21
Total price risk management liabilities	28	21
LG And E And KU Energy LLC [Member] | Level 3 [Member]
Assets
Cash and cash equivalents	0	0
Cash collateral posted to counterparties	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	5	15
Cash collateral posted to counterparties	2	0
Price risk management assets:
Total Assets	7	15
Price risk management liabilities:
Interest rate swaps	28	21
Total price risk management liabilities	28	21
Louisville Gas And Electric Co [Member] | Level 1 [Member]
Assets
Cash and cash equivalents	5	15
Cash collateral posted to counterparties	2	0
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
Cash collateral posted to counterparties	0	0
Price risk management assets:
Total Assets	0	0
Price risk management liabilities:
Interest rate swaps	28	21
Total price risk management liabilities	28	21
Louisville Gas And Electric Co [Member] | Level 3 [Member]
Assets
Cash and cash equivalents	0	0
Cash collateral posted to counterparties	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	145	12
Price risk management assets:
Total Assets	145	12
Kentucky Utilities Co [Member] | Level 1 [Member]
Assets
Cash and cash equivalents	145	12
Price risk management assets:
Total Assets	145	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