Fair Value Measurements - Assets and Liabilities Measured on Recurring Basis Table (Details) - Recurring Fair Value Measurements [Member] - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Assets
Cash and cash equivalents	$ 518	$ 621
Restricted cash and cash equivalents	22	22
Special Use Funds [Abstract]
Money market fund	3	59
Commingled debt fund measured at NAV	31	0
Commingled equity fund measured at NAV	29	0
Total special use funds	63	59
Price risk management assets:
Foreign currency contracts	163	202
Cross-currency swaps	118	135
Total price risk management assets	281	337
Total Assets	884	1,039
Price risk management liabilities:
Interest rate swaps	21	20
Foreign currency contracts	13	2
Total price risk management liabilities	34	22
Level 1 [Member]
Assets
Cash and cash equivalents	518	621
Restricted cash and cash equivalents	22	22
Special Use Funds [Abstract]
Money market fund	3	59
Total special use funds	3	59
Price risk management assets:
Foreign currency contracts	0	0
Cross-currency swaps	0	0
Total price risk management assets	0	0
Total Assets	543	702
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	163	202
Cross-currency swaps	118	135
Total price risk management assets	281	337
Total Assets	281	337
Price risk management liabilities:
Interest rate swaps	21	20
Foreign currency contracts	13	2
Total price risk management liabilities	34	22
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	23	267
Restricted cash and cash equivalents	2	2
Price risk management assets:
Total Assets	25	269
PPL Electric Utilities Corp [Member] | Level 1 [Member]
Assets
Cash and cash equivalents	23	267
Restricted cash and cash equivalents	2	2
Price risk management assets:
Total Assets	25	269
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	22	24
Price risk management assets:
Total Assets	22	24
Price risk management liabilities:
Interest rate swaps	21	20
Total price risk management liabilities	21	20
LG And E And KU Energy LLC [Member] | Level 1 [Member]
Assets
Cash and cash equivalents	22	24
Price risk management assets:
Total Assets	22	24
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	21	20
Total price risk management liabilities	21	20
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	9	10
Price risk management assets:
Total Assets	9	10
Price risk management liabilities:
Interest rate swaps	21	20
Total price risk management liabilities	21	20
Louisville Gas And Electric Co [Member] | Level 1 [Member]
Assets
Cash and cash equivalents	9	10
Price risk management assets:
Total Assets	9	10
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	21	20
Total price risk management liabilities	21	20
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	13	14
Price risk management assets:
Total Assets	13	14
Kentucky Utilities Co [Member] | Level 1 [Member]
Assets
Cash and cash equivalents	13	14
Price risk management assets:
Total Assets	13	14
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