Fair Value Measurements - Assets and Liabilities Measured on Recurring Basis Table (Details) - Recurring Fair Value Measurements [Member] - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Assets
Cash and cash equivalents	$ 915	$ 815
Restricted cash and cash equivalents	21	21
Special Use Funds [Abstract]
Money market fund	1	0
Commingled debt fund measured at NAV	29	29
Commingled equity fund measured at NAV	22	27
Total special use funds	52	56
Price risk management assets:
Foreign currency contracts	190	142
Cross-currency swaps	169	154
Total price risk management assets	359	296
Total Assets	1,347	1,188
Price risk management liabilities:
Interest rate swaps	34	21
Foreign currency contracts	0	5
Total price risk management liabilities	34	26
Level 1 [Member]
Assets
Cash and cash equivalents	915	815
Restricted cash and cash equivalents	21	21
Special Use Funds [Abstract]
Money market fund	1	0
Total special use funds	1	0
Price risk management assets:
Foreign currency contracts	0	0
Cross-currency swaps	0	0
Total price risk management assets	0	0
Total Assets	937	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]
Money market fund	0	0
Total special use funds	0	0
Price risk management assets:
Foreign currency contracts	190	142
Cross-currency swaps	169	154
Total price risk management assets	359	296
Total Assets	359	296
Price risk management liabilities:
Interest rate swaps	34	21
Foreign currency contracts	0	5
Total price risk management liabilities	34	26
Level 3 [Member]
Assets
Cash and cash equivalents	0	0
Restricted cash and cash equivalents	0	0
Special Use Funds [Abstract]
Money market fund	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	33	262
Restricted cash and cash equivalents	2	2
Price risk management assets:
Total Assets	35	264
PPL Electric Utilities Corp [Member] | Level 1 [Member]
Assets
Cash and cash equivalents	33	262
Restricted cash and cash equivalents	2	2
Price risk management assets:
Total Assets	35	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	47	27
Cash collateral posted to counterparties	1	0
Price risk management assets:
Total Assets	48	27
Price risk management liabilities:
Interest rate swaps	29	21
Total price risk management liabilities	29	21
LG And E And KU Energy LLC [Member] | Level 1 [Member]
Assets
Cash and cash equivalents	47	27
Cash collateral posted to counterparties	1	0
Price risk management assets:
Total Assets	48	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	29	21
Total price risk management liabilities	29	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	7	15
Cash collateral posted to counterparties	1	0
Price risk management assets:
Total Assets	8	15
Price risk management liabilities:
Interest rate swaps	29	21
Total price risk management liabilities	29	21
Louisville Gas And Electric Co [Member] | Level 1 [Member]
Assets
Cash and cash equivalents	7	15
Cash collateral posted to counterparties	1	0
Price risk management assets:
Total Assets	8	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	29	21
Total price risk management liabilities	29	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	40	12
Price risk management assets:
Total Assets	40	12
Kentucky Utilities Co [Member] | Level 1 [Member]
Assets
Cash and cash equivalents	40	12
Price risk management assets:
Total Assets	40	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