Income and Other Taxes (Deferred Tax Assets and Liabilities and Loss Carryforwards) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income (Loss) from Continuing Operations (Details) [Abstract]
Domestic income	$ 874	$ 1,463	$ 968
Foreign income	1,038	1,087	1,100
Income Before Income Taxes	1,912	2,550	2,068
Deferred Tax Assets
Deferred investment tax credits	33	51
Regulatory liabilities	62	94
Income taxes due to customer	499	0
Accrued pension costs	159	250
Federal loss carryforwards	356	565
State loss carryforwards	409	326
Federal and state tax credit carryforwards	455	256
Foreign capital loss carryforwards	329	302
Foreign loss carryforwards	2	3
Foreign - pensions	(32)	41
Foreign - regulatory obligations	2	6
Foreign - other	7	5
Contributions in aid of construction	134	141
Domestic - other	104	188
Unrealized losses on qualifying derivatives	10	20
Valuation allowances	(838)	(593)
Total deferred tax assets	1,691	1,655
Deferred Tax Liabilities
Domestic plant - net	3,168	4,325
Taxes recoverable through future rates	0	170
Regulatory assets	211	343
Reacquired debt costs	15	25
Foreign plant - net	726	640
Domestic - other	9	14
Total deferred tax liabilities	4,129	5,517
Net deferred tax liability	2,438	3,862
Loss carryforwards
Federal loss carryforwards	356	565
Federal [Member]
Deferred Tax Assets
Federal loss carryforwards	349
Loss carryforwards
Net operating losses	1,662
Charitable contributions	36
Federal loss carryforwards	349
Charitable contribution carryforwards	7
Loss carryforward valuation allowance on net operating losses	0
Charitable Contributions Loss Carryforwards valuation allowance	0
State [Member]
Deferred Tax Assets
State loss carryforwards	407
Loss carryforwards
Net operating losses	5,512
Charitable contributions	26
Charitable contribution carryforwards	2
Loss carryforward valuation allowance on net operating losses	(348)
Charitable Contributions Loss Carryforwards valuation allowance	0
Foreign Tax Authority [Member]
Deferred Tax Assets
Foreign capital loss carryforwards	329
Foreign loss carryforwards	2
Loss carryforwards
Net operating losses	10
Capital losses	1,938
Loss carryforward valuation allowance on net operating losses	0
Loss carryforward valuation allowance on capital losses	(329)
Tax Cuts And Jobs Act [Member]
Deferred Tax Liabilities
Net deferred tax liability	101
Other Noncurrent Assets [Member]
Deferred Tax Liabilities
Deferred Tax Assets, State Taxes	$ 24	27
Minimum [Member] | Federal [Member]
Loss carryforwards
Expiration - operating losses	Dec. 31, 2029
Expiration - charitable contributions	Dec. 31, 2020
Minimum [Member] | State [Member]
Loss carryforwards
Expiration - operating losses	Dec. 31, 2018
Expiration - charitable contributions	Dec. 31, 2018
Maximum [Member] | Federal [Member]
Loss carryforwards
Expiration - operating losses	Dec. 31, 2037
Expiration - charitable contributions	Dec. 31, 2022
Maximum [Member] | State [Member]
Loss carryforwards
Expiration - operating losses	Dec. 31, 2037
Expiration - charitable contributions	Dec. 31, 2022
PPL Electric Utilities Corp [Member]
Income (Loss) from Continuing Operations (Details) [Abstract]
Income Before Income Taxes	$ 575	552	416
Deferred Tax Assets
Regulatory liabilities	25	34
Income taxes due to customer	193	0
Accrued pension costs	63	107
Federal loss carryforwards	91	147
State loss carryforwards	19	22
Contributions in aid of construction	117	112
Domestic - other	45	81
Total deferred tax assets	553	503
Deferred Tax Liabilities
Domestic plant - net	1,544	2,001
Taxes recoverable through future rates	0	141
Regulatory assets	150	240
Reacquired debt costs	8	15
Domestic - other	5	5
Total deferred tax liabilities	1,707	2,402
Net deferred tax liability	1,154	1,899
Loss carryforwards
Federal loss carryforwards	91	147
PPL Electric Utilities Corp [Member] | Federal [Member]
Deferred Tax Assets
Federal loss carryforwards	89
Loss carryforwards
Net operating losses	426
Charitable contributions	8
Federal loss carryforwards	89
Charitable contribution carryforwards	2
PPL Electric Utilities Corp [Member] | State [Member]
Deferred Tax Assets
State loss carryforwards	18
Loss carryforwards
Net operating losses	233
Charitable contributions	13
Charitable contribution carryforwards	$ 1
PPL Electric Utilities Corp [Member] | Minimum [Member] | Federal [Member]
Loss carryforwards
Expiration - operating losses	Dec. 31, 2031
Expiration - charitable contributions	Dec. 31, 2020
PPL Electric Utilities Corp [Member] | Minimum [Member] | State [Member]
Loss carryforwards
Expiration - operating losses	Dec. 31, 2030
Expiration - charitable contributions	Dec. 31, 2018
PPL Electric Utilities Corp [Member] | Maximum [Member] | Federal [Member]
Loss carryforwards
Expiration - operating losses	Dec. 31, 2037
Expiration - charitable contributions	Dec. 31, 2022
PPL Electric Utilities Corp [Member] | Maximum [Member] | State [Member]
Loss carryforwards
Expiration - operating losses	Dec. 31, 2032
Expiration - charitable contributions	Dec. 31, 2022
LG And E And KU Energy LLC [Member]
Income (Loss) from Continuing Operations (Details) [Abstract]
Income Before Income Taxes	$ 691	686	603
Deferred Tax Assets
Deferred investment tax credits	33	51
Regulatory liabilities	37	60
Income taxes due to customer	305	15
Accrued pension costs	29	58
Federal loss carryforwards	150	248
State loss carryforwards	41	35
Federal and state tax credit carryforwards	181	186
Contributions in aid of construction	17	29
Domestic - other	26	49
Unrealized losses on qualifying derivatives	7	12
Valuation allowances	(8)	(11)
Total deferred tax assets	818	732
Deferred Tax Liabilities
Domestic plant - net	1,615	2,352
Regulatory assets	61	102
Domestic - other	8	13
Total deferred tax liabilities	1,684	2,467
Net deferred tax liability	866	1,735
Loss carryforwards
Federal loss carryforwards	150	248
LG And E And KU Energy LLC [Member] | Federal [Member]
Deferred Tax Assets
Federal loss carryforwards	150
Loss carryforwards
Net operating losses	713
Charitable contributions	14
Federal loss carryforwards	150
Charitable contribution carryforwards	3
Loss carryforward valuation allowance on net operating losses	0
Charitable Contributions Loss Carryforwards valuation allowance	0
LG And E And KU Energy LLC [Member] | State [Member]
Deferred Tax Assets
Federal loss carryforwards	41
Loss carryforwards
Net operating losses	874
Federal loss carryforwards	41
Loss carryforward valuation allowance on net operating losses	$ 0
LG And E And KU Energy LLC [Member] | Minimum [Member] | Federal [Member]
Loss carryforwards
Expiration - operating losses	Dec. 31, 2028
Expiration - charitable contributions	Dec. 31, 2020
LG And E And KU Energy LLC [Member] | Minimum [Member] | State [Member]
Loss carryforwards
Expiration - operating losses	Dec. 31, 2028
LG And E And KU Energy LLC [Member] | Maximum [Member] | Federal [Member]
Loss carryforwards
Expiration - operating losses	Dec. 31, 2037
Expiration - charitable contributions	Dec. 31, 2022
LG And E And KU Energy LLC [Member] | Maximum [Member] | State [Member]
Loss carryforwards
Expiration - operating losses	Dec. 31, 2037
Louisville Gas And Electric Co [Member]
Income (Loss) from Continuing Operations (Details) [Abstract]
Income Before Income Taxes	$ 344	329	299
Deferred Tax Assets
Deferred investment tax credits	9	14
Regulatory liabilities	21	34
Income taxes due to customer	142	17
Federal loss carryforwards	29	80
Contributions in aid of construction	11	18
Domestic - other	12	17
Unrealized losses on qualifying derivatives	7	12
Total deferred tax assets	231	192
Deferred Tax Liabilities
Domestic plant - net	724	1,058
Regulatory assets	40	65
Accrued pension costs	34	35
Domestic - other	5	8
Total deferred tax liabilities	803	1,166
Net deferred tax liability	572	974
Loss carryforwards
Federal loss carryforwards	29	80
Louisville Gas And Electric Co [Member] | Federal [Member]
Loss carryforwards
Net operating losses	$ 140
Expiration - operating losses	Dec. 31, 2035
Kentucky Utilities Co [Member]
Income (Loss) from Continuing Operations (Details) [Abstract]
Income Before Income Taxes	$ 418	428	$ 374
Deferred Tax Assets
Deferred investment tax credits	24	37
Regulatory liabilities	16	26
Income taxes due to customer	163	0
Federal loss carryforwards	13	79
Contributions in aid of construction	6	11
Domestic - other	9	11
Total deferred tax assets	231	164
Deferred Tax Liabilities
Domestic plant - net	882	1,280
Regulatory assets	21	37
Accrued pension costs	17	12
Domestic - other	2	5
Total deferred tax liabilities	922	1,334
Net deferred tax liability	691	1,170
Loss carryforwards
Federal loss carryforwards	13	$ 79
Kentucky Utilities Co [Member] | Federal [Member]
Loss carryforwards
Net operating losses	$ 61
Expiration - operating losses	Dec. 31, 2035