Income and Other Taxes (Credit Carryforwards and Valuation Allowances and Reserves) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Credit carryforwards
Deferred tax asset credit carryforwards	$ 402	$ 392
Deferred Tax Assets, Valuation Allowances	834	808
Tax Cuts And Jobs Act [Member]
Credit carryforwards
Credit Carryforward Valuation Allowance Foreign Tax Credits			$ 122
Taxable Deemed Dividend			462
Deferred Tax Assets, Foreign Tax Credit Carryforwards			205
Permanently reinvested cumulative undistributed foreign earnings	7,500
Valuation Allowances and Reserves (Details) [Roll Forward]
Increase of the valuation allowance as a result of the expected future utilization of foreign tax credits			145
Investment Tax Credit [Member] | Federal [Member]
Credit carryforwards
Deferred tax asset credit carryforwards	133
Credit Carryforward Valuation Allowance Investment Tax Credit	0
Alternative Minimum Tax Credit [Member] | Federal [Member]
Credit carryforwards
Deferred tax asset credit carryforwards	8
Credit Carryforward Valuation Allowance Alternative Minimum Tax Credit	0
Foreign Tax Credit [Member] | Federal [Member]
Credit carryforwards
Deferred tax asset credit carryforwards	218
Credit Carryforward Valuation Allowance Foreign Tax Credits	(113)
Foreign Tax Credit [Member] | Federal [Member] | Tax Year 2016 [Member] | Tax Cuts And Jobs Act [Member]
Credit carryforwards
Deferred Tax Assets, Foreign Tax Credit Carryforwards	62
Foreign Tax Credit [Member] | Federal [Member] | Tax Year 2017 [Member] | Tax Cuts And Jobs Act [Member]
Credit carryforwards
Deferred Tax Assets, Foreign Tax Credit Carryforwards	156
Recycling Tax Credit [Member] | State [Member]
Credit carryforwards
Deferred tax asset credit carryforwards	18
Credit Carryforward Valuation Allowance Other	0
Other [Member] | Federal [Member]
Credit carryforwards
Deferred tax asset credit carryforwards	24
Credit Carryforward Valuation Allowance Other	(6)
Other [Member] | State [Member]
Credit carryforwards
Deferred tax asset credit carryforwards	1
Credit Carryforward Valuation Allowance Other	0
Valuation Allowance Of Deferred Tax Assets [Member]
Valuation Allowances and Reserves (Details) [Roll Forward]
Balance at beginning of period	808	838	593
Additions charged to income	31	26	256
Additions charged to other accounts	0	0	0
Deductions	5	56	11
Balance at end of period	834	808	838
Decrease of the valuation allowance as a result of a change in foreign tax credits available		35
Decrease of the valuation allowance as a result of the change in currency exchange rates		19
Increase of the valuation allowance as a result of the expected future utilization of foreign tax credits			145
Increase of the valuation allowance as a result of the reduction in the U.S. federal corporate income tax rate			62
LG And E And KU Energy LLC [Member]
Credit carryforwards
State tax credit carryforwards	19	1
Deferred tax asset credit carryforwards	162	169
Deferred Tax Assets, Valuation Allowances	6	8
LG And E And KU Energy LLC [Member] | Investment Tax Credit [Member] | Federal [Member]
Credit carryforwards
Deferred tax asset credit carryforwards	133
Credit Carryforward Valuation Allowance Investment Tax Credit	0
LG And E And KU Energy LLC [Member] | Alternative Minimum Tax Credit [Member] | Federal [Member]
Credit carryforwards
Deferred tax asset credit carryforwards	7
Credit Carryforward Valuation Allowance Alternative Minimum Tax Credit	0
LG And E And KU Energy LLC [Member] | Recycling Tax Credit [Member] | State [Member]
Credit carryforwards
Deferred tax asset credit carryforwards	18
Credit Carryforward Valuation Allowance Other	0
LG And E And KU Energy LLC [Member] | Other [Member] | Federal [Member]
Credit carryforwards
Deferred tax asset credit carryforwards	22
Credit Carryforward Valuation Allowance Other	(6)
LG And E And KU Energy LLC [Member] | Other [Member] | State [Member]
Credit carryforwards
Deferred tax asset credit carryforwards	1
Credit Carryforward Valuation Allowance Other	0
LG And E And KU Energy LLC [Member] | Valuation Allowance Of Deferred Tax Assets [Member]
Valuation Allowances and Reserves (Details) [Roll Forward]
Balance at beginning of period	8	8	11
Additions charged to other accounts	3	0	4
Deductions	5	0	7
Balance at end of period	6	8	$ 8
Louisville Gas And Electric Co [Member]
Credit carryforwards
State tax credit carryforwards	14	0
Deferred Tax Assets, Valuation Allowances	14	0
Louisville Gas And Electric Co [Member] | Other [Member] | Federal [Member]
Credit carryforwards
State tax credit carryforwards	14
Deferred Tax Assets, Valuation Allowances	14
Kentucky Utilities Co [Member]
Credit carryforwards
State tax credit carryforwards	5	0
Deferred Tax Assets, Valuation Allowances	4	$ 0
Kentucky Utilities Co [Member] | Other [Member] | Federal [Member]
Credit carryforwards
State tax credit carryforwards	5
Deferred Tax Assets, Valuation Allowances	4
Kentucky Utilities Co [Member] | Other [Member] | Federal [Member] | Tax Credit Carryforward Expiration Year 2028 [Member]
Credit carryforwards
State tax credit carryforwards	4
Kentucky Utilities Co [Member] | Other [Member] | Federal [Member] | Tax Credit Carryforward Expiration Indefinite [Member]
Credit carryforwards
State tax credit carryforwards	$ 1