Income and Other Taxes (Deferred Tax Assets and Liabilities and Loss Carryforwards) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013	Dec. 31, 2012
Income (Loss) from Continuing Operations (Details) [Abstract]
Domestic income	$ 1,157		$ 201	$ 1,000
Foreign income	1,207		1,059	1,009
Income (Loss) Before Income Taxes	2,364		1,260	2,009
Deferred Tax Assets
Deferred investment tax credits	63	[1]	137
Regulatory obligations	131		144
Accrued pension costs	298		140
Federal loss carryforwards	151		331
State loss carryforwards	304		304
Federal and state tax credit carryforwards	209	[1]	332
Foreign capital loss carryforwards	446		467
Foreign loss carryforwards	6		6
Foreign - pensions	182		202
Foreign - regulatory obligations	23		26
Foreign - other	11		12
Contributions in aid of construction	138		137
Domestic - other	273		211
Unrealized losses on qualifying derivatives	46		0
Valuation allowances	(700)		(663)
Total deferred tax assets	1,581		1,786
Deferred Tax Liabilities
Domestic plant - net	4,453		4,073
Taxes recoverable through future rates	156		151
Unrealized gain on qualifying derivatives	28		37
Other regulatory assets	322		244
Reacquired debt costs	31		34
Foreign plant - net	854		859
Domestic - other	58		78
Total deferred tax liabilities	5,902		5,476
Net deferred tax liability	4,321		3,690
Federal [Member]
Loss carryforwards
Net operating losses	432	[2]
Federal [Member] | Minimum [Member]
Loss carryforwards
Expiration - operating losses	Dec. 31, 2031
Federal [Member] | Maximum [Member]
Loss carryforwards
Expiration - operating losses	Dec. 31, 2032
State [Member]
Loss carryforwards
Net operating losses	5,059	[2],[3]
Charitable contributions	33
Loss carryfoward valuation allowance on net operating losses	238
State [Member] | Minimum [Member]
Loss carryforwards
Expiration - operating losses	Dec. 31, 2017
Expiration - capital losses	Dec. 31, 2015
State [Member] | Maximum [Member]
Loss carryforwards
Expiration - operating losses	Dec. 31, 2034
Expiration - capital losses	Dec. 31, 2018
Foreign [Member]
Loss carryforwards
Net operating losses	29	[4]
Capital losses	2,231	[5]
Loss carryfoward valuation allowance on net operating losses	6
Loss carryfoward valuation allowance on capital losses	446
PPL Energy Supply LLC [Member]
Income (Loss) from Continuing Operations (Details) [Abstract]
Income (Loss) Before Income Taxes	303		(420)	665
Deferred Tax Assets
Deferred investment tax credits	11	[1]	84
Accrued pension costs	98		39
Federal loss carryforwards	22		28
State loss carryforwards	79		80
Federal and state tax credit carryforwards	13	[1]	131
Domestic - other	79		69
Valuation allowances	(78)		(78)
Total deferred tax assets	224		353
Deferred Tax Liabilities
Domestic plant - net	1,374		1,392
Unrealized gain on qualifying derivatives	28		38
Domestic - other	42		46
Total deferred tax liabilities	1,444		1,476
Net deferred tax liability	1,220		1,123
PPL Energy Supply LLC [Member] | Federal [Member]
Loss carryforwards
Net operating losses	63
PPL Energy Supply LLC [Member] | Federal [Member] | Minimum [Member]
Loss carryforwards
Expiration - operating losses	Dec. 31, 2031
PPL Energy Supply LLC [Member] | Federal [Member] | Maximum [Member]
Loss carryforwards
Expiration - operating losses	Dec. 31, 2032
PPL Energy Supply LLC [Member] | State [Member]
Loss carryforwards
Net operating losses	1,228	[6]
PPL Energy Supply LLC [Member] | State [Member] | Minimum [Member]
Loss carryforwards
Expiration - operating losses	Dec. 31, 2018
PPL Energy Supply LLC [Member] | State [Member] | Maximum [Member]
Loss carryforwards
Expiration - operating losses	Dec. 31, 2034
PPL Electric Utilities Corp [Member]
Income (Loss) from Continuing Operations (Details) [Abstract]
Income (Loss) Before Income Taxes	423		317	204
Deferred Tax Assets
Regulatory obligations	39		38
Accrued pension costs	85		42
Federal loss carryforwards	51		72
State loss carryforwards	30		35
Contributions in aid of construction	110		109
Domestic - other	54		45
Total deferred tax assets	369		341
Deferred Tax Liabilities
Domestic plant - net	1,453		1,366
Taxes recoverable through future rates	132		129
Other regulatory assets	173		129
Reacquired debt costs	20		23
Domestic - other	16		8
Total deferred tax liabilities	1,794		1,655
Net deferred tax liability	1,425		1,314
PPL Electric Utilities Corp [Member] | Federal [Member]
Loss carryforwards
Net operating losses	146
PPL Electric Utilities Corp [Member] | Federal [Member] | Minimum [Member]
Loss carryforwards
Expiration - operating losses	Dec. 31, 2031
PPL Electric Utilities Corp [Member] | Federal [Member] | Maximum [Member]
Loss carryforwards
Expiration - operating losses	Dec. 31, 2032
PPL Electric Utilities Corp [Member] | State [Member]
Loss carryforwards
Net operating losses	467
PPL Electric Utilities Corp [Member] | State [Member] | Minimum [Member]
Loss carryforwards
Expiration - operating losses	Dec. 31, 2030
PPL Electric Utilities Corp [Member] | State [Member] | Maximum [Member]
Loss carryforwards
Expiration - operating losses	Dec. 31, 2032
LG And E And KU Energy LLC [Member]
Income (Loss) from Continuing Operations (Details) [Abstract]
Income (Loss) Before Income Taxes	553		551	331
Deferred Tax Assets
Deferred investment tax credits	51		52
Regulatory obligations	92		107
Accrued pension costs	53		26
Federal loss carryforwards	82		222
State capital loss carryforward	0		4
Income taxes due to customers	20		23
Federal and state tax credit carryforwards	182		179
Domestic - other	44		43
Unrealized losses on qualifying derivatives	45		14
Valuation allowances	0		(4)
Total deferred tax assets	569		666
Deferred Tax Liabilities
Domestic plant - net	1,639		1,327
Other regulatory assets	143		133
Domestic - other	12		12
Total deferred tax liabilities	1,794		1,472
Net deferred tax liability	1,225		806
LG And E And KU Energy LLC [Member] | Federal [Member]
Loss carryforwards
Net operating losses	132
LG And E And KU Energy LLC [Member] | Federal [Member] | Minimum [Member]
Loss carryforwards
Expiration - operating losses	Dec. 31, 2031
LG And E And KU Energy LLC [Member] | Federal [Member] | Maximum [Member]
Loss carryforwards
Expiration - operating losses	Dec. 31, 2032
LG And E And KU Energy LLC [Member] | State [Member]
Loss carryforwards
Net operating losses	927
Capital losses	1
Expiration - capital losses	Dec. 31, 2016
LG And E And KU Energy LLC [Member] | State [Member] | Minimum [Member]
Loss carryforwards
Expiration - operating losses	Dec. 31, 2028
LG And E And KU Energy LLC [Member] | State [Member] | Maximum [Member]
Loss carryforwards
Expiration - operating losses	Dec. 31, 2032
Louisville Gas And Electric Co [Member]
Income (Loss) from Continuing Operations (Details) [Abstract]
Income (Loss) Before Income Taxes	272		257	192
Deferred Tax Assets
Deferred investment tax credits	14		15
Regulatory obligations	51		59
Income taxes due to customers	18		19
Domestic - other	9		14
Unrealized losses on qualifying derivatives	32		14
Total deferred tax assets	124		121
Deferred Tax Liabilities
Domestic plant - net	698		585
Other regulatory assets	90		83
Accrued pension costs	28		24
Domestic - other	8		8
Total deferred tax liabilities	824		700
Net deferred tax liability	700		579
Kentucky Utilities Co [Member]
Income (Loss) from Continuing Operations (Details) [Abstract]
Income (Loss) Before Income Taxes	355		360	215
Deferred Tax Assets
Deferred investment tax credits	37		38
Regulatory obligations	41		47
Federal loss carryforwards	0		23
Income taxes due to customers	2		4
Domestic - other	7		8
Unrealized losses on qualifying derivatives	13		0
Total deferred tax assets	100		120
Deferred Tax Liabilities
Domestic plant - net	922		721
Other regulatory assets	53		50
Domestic - other	7		4
Total deferred tax liabilities	982		775
Net deferred tax liability	$ 882		$ 655

[1] During 2014, PPL accepted U.S. government grants for hydroelectric plant expansions resulting in reductions of investment tax credits previously claimedand reductions in the carrying value of the related plants. See Note 8 for additional information.

[2] Includes an insignificant amount of federal and state net operating loss carryforwards from excess tax deductions related to stock compensation for which a tax benefit will be recorded in Equity when realized.

[3] A valuation allowance of $238 million has been recorded against the deferred tax assets for these losses

[4] A valuation allowance of $6 million has been recorded against the deferred tax assets for these losses.

[5] A valuation allowance of $446 million has been recorded against the deferred tax assets for these losses.

[6] A valuation allowance of $78 million has been recorded against the deferred tax assets for these losses.