Fair Value Measurements - Assets and Liabilities Measured on Recurring Basis Table (Details) - Recurring Fair Value Measurements [Member] - USD ($) $ in Millions	Jun. 30, 2017	Dec. 31, 2016
Assets
Cash and cash equivalents	$ 467	$ 341
Restricted cash and cash equivalents	25	26
Price risk management assets:
Foreign currency contracts	156	211
Cross-currency swaps	158	188
Total price risk management assets	314	399
Total assets	806	766
Price risk management liabilities:
Interest rate swaps	31	31
Foreign currency contracts	104	27
Total price risk management liabilities	135	58
Level 1 [Member]
Assets
Cash and cash equivalents	467	341
Restricted cash and cash equivalents	25	26
Price risk management assets:
Foreign currency contracts	0	0
Cross-currency swaps	0	0
Total price risk management assets	0	0
Total assets	492	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	156	211
Cross-currency swaps	158	188
Total price risk management assets	314	399
Total assets	314	399
Price risk management liabilities:
Interest rate swaps	31	31
Foreign currency contracts	104	27
Total price risk management liabilities	135	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	59	13
Restricted cash and cash equivalents	2	2
Price risk management assets:
Total assets	61	15
PPL Electric Utilities Corp [Member] | Level 1 [Member]
Assets
Cash and cash equivalents	59	13
Restricted cash and cash equivalents	2	2
Price risk management assets:
Total assets	61	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	19	13
Cash collateral posted to counterparties	2	3
Price risk management assets:
Total assets	21	16
Price risk management liabilities:
Interest rate swaps	30	31
Total price risk management liabilities	30	31
LG And E And KU Energy LLC [Member] | Level 1 [Member]
Assets
Cash and cash equivalents	19	13
Cash collateral posted to counterparties	2	3
Price risk management assets:
Total assets	21	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
Cash collateral posted to counterparties	0	0
Price risk management assets:
Total assets	0	0
Price risk management liabilities:
Interest rate swaps	30	31
Total price risk management liabilities	30	31
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	5
Cash collateral posted to counterparties	2	3
Price risk management assets:
Total assets	9	8
Price risk management liabilities:
Interest rate swaps	30	31
Total price risk management liabilities	30	31
Louisville Gas And Electric Co [Member] | Level 1 [Member]
Assets
Cash and cash equivalents	7	5
Cash collateral posted to counterparties	2	3
Price risk management assets:
Total assets	9	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
Cash collateral posted to counterparties	0	0
Price risk management assets:
Total assets	0	0
Price risk management liabilities:
Interest rate swaps	30	31
Total price risk management liabilities	30	31
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	12	7
Price risk management assets:
Total assets	12	7
Kentucky Utilities Co [Member] | Level 1 [Member]
Assets
Cash and cash equivalents	12	7
Price risk management assets:
Total assets	12	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