Fair Value Measurements (Assets and Liabilities Measured on Recurring Basis Table) (Details) - Recurring [Member] - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Assets
Cash and cash equivalents	$ 485	$ 341
Restricted cash and cash equivalents	26	26
Price risk management assets:
Foreign currency contracts	163	211
Cross-currency swaps	101	188
Total price risk management assets	264	399
Total assets	775	766
Price risk management liabilities:
Interest rate swaps	26	31
Foreign currency contracts	148	27
Total price risk management liabilities	174	58
Level 1 [Member]
Assets
Cash and cash equivalents	485	341
Restricted cash and cash equivalents	26	26
Price risk management assets:
Foreign currency contracts	0	0
Cross-currency swaps	0	0
Total price risk management assets	0	0
Total assets	511	367
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
Price risk management assets:
Foreign currency contracts	163	211
Cross-currency swaps	101	188
Total price risk management assets	264	399
Total assets	264	399
Price risk management liabilities:
Interest rate swaps	26	31
Foreign currency contracts	148	27
Total price risk management liabilities	174	58
Level 3 [Member]
Assets
Cash and cash equivalents	0	0
Restricted cash and cash equivalents	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	49	13
Restricted cash and cash equivalents	2	2
Price risk management assets:
Total assets	51	15
PPL Electric Utilities Corp [Member] | Level 1 [Member]
Assets
Cash and cash equivalents	49	13
Restricted cash and cash equivalents	2	2
Price risk management assets:
Total assets	51	15
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	30	13
Price risk management assets:
Cash collateral posted to counterparties	0	3
Total assets	30	16
Price risk management liabilities:
Interest rate swaps	26	31
Total price risk management liabilities	26	31
LG And E And KU Energy LLC [Member] | Level 1 [Member]
Assets
Cash and cash equivalents	30	13
Price risk management assets:
Cash collateral posted to counterparties	0	3
Total assets	30	16
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:
Cash collateral posted to counterparties	0	0
Total assets	0	0
Price risk management liabilities:
Interest rate swaps	26	31
Total price risk management liabilities	26	31
LG And E And KU Energy LLC [Member] | Level 3 [Member]
Assets
Cash and cash equivalents	0	0
Price risk management assets:
Cash collateral posted to counterparties	0	0
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	15	5
Price risk management assets:
Cash collateral posted to counterparties	0	3
Total assets	15	8
Price risk management liabilities:
Interest rate swaps	26	31
Total price risk management liabilities	26	31
Louisville Gas And Electric Co [Member] | Level 1 [Member]
Assets
Cash and cash equivalents	15	5
Price risk management assets:
Cash collateral posted to counterparties	0	3
Total assets	15	8
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:
Cash collateral posted to counterparties	0	0
Total assets	0	0
Price risk management liabilities:
Interest rate swaps	26	31
Total price risk management liabilities	26	31
Louisville Gas And Electric Co [Member] | Level 3 [Member]
Assets
Cash and cash equivalents	0	0
Price risk management assets:
Cash collateral posted to counterparties	0	0
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	15	7
Price risk management assets:
Total assets	15	7
Kentucky Utilities Co [Member] | Level 1 [Member]
Assets
Cash and cash equivalents	15	7
Price risk management assets:
Total assets	15	7
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