Income and Other Taxes (Deferred Tax Assets and Liabilities and Loss Carryforwards) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income (Loss) from Continuing Operations (Details) [Abstract]
Domestic income	$ 994	$ 1,715	$ 952
Foreign income	1,088	486	287
Income from Continuing Operations Before Income Taxes	2,082	2,201	1,239
Deferred Tax Assets
Deferred investment tax credits	130	113
Regulatory obligations	124	149
Accrued pension costs	276	325
Federal loss carryforwards	524	305
State loss carryforwards	305	272
Federal and state tax credit carryforwards	287	240
Foreign capital loss carryforwards	525	578
Foreign loss carryforwards	6	7
Foreign - pensions	254	74
Foreign - regulatory obligations	27	67
Foreign - other	16	21
Contributions in aid of construction	134	133
Domestic - other	239	229
Valuation allowances	(706)	(724)
Total deferred tax assets	2,141	1,789
Deferred Tax Liabilities
Domestic plant - net	3,967	3,465
Taxes recoverable through future rates	141	137
Unrealized gain on qualifying derivatives	122	331
Regulatory assets	319	234
Reacquired debt costs	40	93
Foreign plant - net	937	975
Foreign - other		22
Domestic - other	66	103
Total deferred tax liabilities	5,592	5,360
Net deferred tax liability	3,451	3,571
Federal [Member]
Loss carryforwards
Net operating losses	1,481
Charitable contributions	19
Expiration - operating losses	2028-2032
Expiration - charitable contributions	2016-2017
State [Member]
Loss carryforwards
Net operating losses	5,099
Capital losses	138
Expiration - operating losses	2013-2032
Expiration - capital losses	2013-2016
Foreign [Member]
Loss carryforwards
Net operating losses	27
Capital losses	2,282
Expiration - operating losses	Indefinite
Expiration - capital losses	Indefinite
PPL Energy Supply LLC [Member]
Income (Loss) from Continuing Operations (Details) [Abstract]
Income from Continuing Operations Before Income Taxes	738	1,212	881
Deferred Tax Assets
Deferred investment tax credits	75	55
Accrued pension costs	94	100
Federal loss carryforwards	51	1
State loss carryforwards	79	78
Federal and state tax credit carryforwards	113	58
Domestic - other	68	80
Valuation allowances	(74)	(72)
Total deferred tax assets	406	300
Deferred Tax Liabilities
Domestic plant - net	1,579	1,407
Unrealized gain on qualifying derivatives	173	380
Domestic - other	44	51
Total deferred tax liabilities	1,796	1,838
Net deferred tax liability	1,390	1,538
PPL Energy Supply LLC [Member] | Federal [Member]
Loss carryforwards
Net operating losses	143
Charitable contributions	3
Expiration - operating losses	2031-2032
Expiration - charitable contributions	2016
PPL Energy Supply LLC [Member] | State [Member]
Loss carryforwards
Net operating losses	1,202
Expiration - operating losses	2013-2032
PPL Electric Utilities Corp [Member]
Income (Loss) from Continuing Operations (Details) [Abstract]
Income from Continuing Operations Before Income Taxes	204	257	192
Deferred Tax Assets
Regulatory obligations	24	28
Accrued pension costs	81	93
Federal loss carryforwards	81	3
State loss carryforwards	39	26
Contributions in aid of construction	106	104
Domestic - other	46	29
Total deferred tax assets	377	283
Deferred Tax Liabilities
Domestic plant - net	1,229	1,078
Taxes recoverable through future rates	122	120
Regulatory assets	174	127
Reacquired debt costs	27	32
Domestic - other	12	16
Total deferred tax liabilities	1,564	1,373
Net deferred tax liability	1,187	1,090
PPL Electric Utilities Corp [Member] | Federal [Member]
Loss carryforwards
Net operating losses	229
Charitable contributions	2
Expiration - operating losses	2031-2032
Expiration - charitable contributions	2016
PPL Electric Utilities Corp [Member] | State [Member]
Loss carryforwards
Net operating losses	597
Expiration - operating losses	2030-2032
LG And E And KU Energy LLC [Member]
Deferred Tax Assets
Deferred investment tax credits	54	56
Regulatory obligations	99	124
Accrued pension costs	42	67
State capital loss carryforward	5	5
Federal loss carryforwards	376	318
Income taxes due to customers	26	30
Federal and state tax credit carryforwards	170	170
Domestic - other	41	30
Valuation allowances	(5)	(5)
Total deferred tax assets	808	795
Deferred Tax Liabilities
Domestic plant - net	1,171	986
Regulatory assets	152	180
Domestic - other	13	25
Total deferred tax liabilities	1,336	1,191
Net deferred tax liability	528	396
LG And E And KU Energy LLC [Member] | Federal [Member]
Loss carryforwards
Net operating losses	948
Expiration - operating losses	2028-2032
LG And E And KU Energy LLC [Member] | State [Member]
Loss carryforwards
Net operating losses	1,173
Capital losses	119
Expiration - operating losses	2028-2032
Expiration - capital losses	2013-2016
Louisville Gas And Electric Co [Member]
Deferred Tax Assets
Deferred investment tax credits	16	17
Regulatory obligations	54	65
Income taxes due to customers	21	23
Domestic - other	9	10
Total deferred tax assets	100	115
Deferred Tax Liabilities
Domestic plant - net	526	462
Regulatory assets	86	98
Accrued pension costs	27	19
Domestic - other	9	9
Total deferred tax liabilities	648	588
Net deferred tax liability	548	473
Louisville Gas And Electric Co [Member] | State [Member]
Loss carryforwards
Net operating losses	22
Expiration - operating losses	2030
Kentucky Utilities Co [Member]
Deferred Tax Assets
Deferred investment tax credits	38	39
Regulatory obligations	45	58
Accrued pension costs	(5)	9
Federal loss carryforwards	20
Income taxes due to customers	5	7
Domestic - other	7	6
Total deferred tax assets	110	119
Deferred Tax Liabilities
Domestic plant - net	623	500
Regulatory assets	65	82
Domestic - other	5	16
Total deferred tax liabilities	693	598
Net deferred tax liability	583	479
Kentucky Utilities Co [Member] | Federal [Member]
Loss carryforwards
Net operating losses	$ 56
Expiration - operating losses	2032