Income and Other Taxes (Income Tax Expense and Reconciliation of Income Tax Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Expense (Benefit)
Current - Federal	$ 6	$ (14)	$ (26)
Current - State	25	21	25
Current - Foreign	45	80	89
Total Current Expense (Benefit)	76	87	88
Deferred - Federal	532	385	699
Deferred - State	88	89	68
Deferred - Foreign	133	86	41
Total Deferred Expense (Benefit), excluding operating loss carry forwards	753	560	808
Amortization of investment tax credit - Federal	(3)	(3)	(4)
Tax expense (benefit) of operating loss carryforwards [Abstract]
Deferred - Federal	(16)	25	(396)
Deferred - State	(26)	(21)	(31)
Total Tax Expense (Benefit) of Operating Loss Carryforwards	(42)	4	(427)
Total income tax from continuing operations	784	648	465
Income tax expense (benefit) from continuing operations [Abstract]
Total income tax expense - Federal	519	393	273
Total income tax expense - State	87	89	62
Total income tax expense - Foreign	178	166	130
Total income tax from continuing operations	784	648	465
Discontinued operations	0	0	(30)
Stock-based compensation recorded to Earnings Reinvested	0	(7)	0
Other comprehensive income	(34)	(6)	(2)
Valuation allowance on state deferred taxes recorded to other comprehensive income	(1)	1	(4)
Total income tax expense (benefits) excluded from incomes taxes from continuing operations	(35)	(12)	(36)
Reconciliation of Income Tax Expense
Federal income tax on Income (Loss) from Continuing Operations Before Income Taxes at statutory tax rate - 35%	$ 669	$ 893	$ 724
Federal statutory rate	35.00%	35.00%	35.00%
Increase (decrease) due to:
State income taxes, net of federal income tax benefit	$ 46	$ 46	$ 31
Valuation allowance adjustments	36	16	24
Stock-based compensation	(3)	(10)	0
Deferred tax impact of U.S. tax reform	220	0	0
Impact of lower U.K. income tax rates	(176)	(177)	(176)
U.S. income tax on foreign earnings - net of foreign tax credit	47	(42)	8
Federal and state tax reserve adjustments	0	0	(22)
Foreign income return adjustments	(8)	2	0
Impact of the United Kingdom Finance Acts on deferred tax balances	(16)	(49)	(91)
Depreciation not normalized	(10)	(10)	(5)
Interest benefit on United Kingdom financing entities	(16)	(17)	(20)
Other	(5)	(4)	(8)
Total increase (decrease)	115	(245)	(259)
Total income tax from continuing operations	$ 784	$ 648	$ 465
Effective income tax rate	41.00%	25.40%	22.50%
Expense related to increased Pennsylvania net operating loss carryforwards expected to be unutilized	$ 16	$ 13	$ 12
Expense related to federal tax credit carryforwards that are expected to expire as a result of future taxable earnings			12
Benefit recorded in continuing operations related to the settlement of the IRS audit for tax years 1998-2011			12
Benefit recorded in continuing operations related to the planned amendment of a prior period tax return.			(9)
Deferred Income Tax Expense Benefit Statutory Tax Rate Change		42	90
Deferred Income Tax Expense Benefit Foreign Pension Contribution	35
Taxes, other than income
State gross receipts	102	100	89
State capital stock	(6)	0	0
Foreign property	127	135	148
Domestic property and other	69	66	62
Total	292	301	299
Previously recorded reserves			17
Income Tax Reconciliation Valuation Allowance Foreign Tax Credits	23
Tax Cuts And Jobs Act [Member]
Income Tax Expense (Benefit)
Deferred Income Tax Expense (Benefit) Tax Rate Change	220
Tax expense (benefit) of operating loss carryforwards [Abstract]
Total income tax from continuing operations	321
Income tax expense (benefit) from continuing operations [Abstract]
Total income tax from continuing operations	321
Increase (decrease) due to:
Total income tax from continuing operations	321
Deferred Income Tax Expense Benefit Tax Reform	83
Taxable Deemed Dividend	462
Taxes, other than income
Deferred Income Tax Expense (Benefit) Net Operating Loss	162
Deferred Income Tax Benefit Foreign Tax Credits	60
Deferred Tax Assets, Foreign Tax Credit Carryforwards	205
Valuation Rollfoward Specific Transaction Additions Foreign Tax Credits	145
Credit Carryforward Valuation Allowance Foreign Tax Credits	122
Credit Carryforward Expected Realization Foreign Tax Credits	83
PPL Electric Utilities Corp [Member]
Income Tax Expense (Benefit)
Current - Federal	(65)	(29)	(80)
Current - State	20	19	23
Total Current Expense (Benefit)	(45)	(10)	(57)
Deferred - Federal	234	193	287
Deferred - State	29	29	12
Total Deferred Expense (Benefit), excluding operating loss carry forwards	263	222	299
Amortization of investment tax credit - Federal	0	0	0
Tax expense (benefit) of operating loss carryforwards [Abstract]
Deferred - Federal	(5)	0	(75)
Deferred - State	0	0	(3)
Total Tax Expense (Benefit) of Operating Loss Carryforwards	(5)	0	(78)
Total income tax from continuing operations	213	212	164
Income tax expense (benefit) from continuing operations [Abstract]
Total income tax expense - Federal	164	164	132
Total income tax expense - State	49	48	32
Total income tax from continuing operations	213	212	164
Reconciliation of Income Tax Expense
Federal income tax on Income (Loss) from Continuing Operations Before Income Taxes at statutory tax rate - 35%	$ 201	$ 193	$ 146
Federal statutory rate	35.00%	35.00%	35.00%
Increase (decrease) due to:
State income taxes, net of federal income tax benefit	$ 36	$ 36	$ 25
Stock-based compensation	(2)	(6)	0
Deferred tax impact of U.S. tax reform	(13)	0	0
Depreciation not normalized	(8)	(8)	(4)
Other	(1)	(3)	(3)
Total increase (decrease)	12	19	18
Total income tax from continuing operations	$ 213	$ 212	$ 164
Effective income tax rate	37.00%	38.40%	39.40%
Taxes, other than income
State gross receipts	$ 102	$ 100	$ 89
Domestic property and other	5	5	5
Total	107	105	94
Previously recorded reserves			17
PPL Electric Utilities Corp [Member] | Tax Cuts And Jobs Act [Member]
Income Tax Expense (Benefit)
Deferred Income Tax Expense (Benefit) Tax Rate Change	(13)
Tax expense (benefit) of operating loss carryforwards [Abstract]
Total income tax from continuing operations	(13)
Income tax expense (benefit) from continuing operations [Abstract]
Total income tax from continuing operations	(13)
Increase (decrease) due to:
Total income tax from continuing operations	(13)
LG And E And KU Energy LLC [Member]
Income Tax Expense (Benefit)
Current - Federal	74	(36)	2
Current - State	6	1	1
Total Current Expense (Benefit)	80	(35)	3
Deferred - Federal	268	248	405
Deferred - State	32	38	32
Total Deferred Expense (Benefit), excluding operating loss carry forwards	300	286	437
Amortization of investment tax credit - Federal	(3)	(3)	(3)
Tax expense (benefit) of operating loss carryforwards [Abstract]
Deferred - Federal	(2)	10	(198)
Deferred - State	0	(1)	0
Total Tax Expense (Benefit) of Operating Loss Carryforwards	(2)	9	(198)
Total income tax from continuing operations	375	257	239
Income tax expense (benefit) from continuing operations [Abstract]
Total income tax expense - Federal	337	219	206
Total income tax expense - State	38	38	33
Total income tax from continuing operations	375	257	239
Other comprehensive income	(10)	(16)	(1)
Reconciliation of Income Tax Expense
Federal income tax on Income (Loss) from Continuing Operations Before Income Taxes at statutory tax rate - 35%	$ 242	$ 240	$ 211
Federal statutory rate	35.00%	35.00%	35.00%
Increase (decrease) due to:
State income taxes, net of federal income tax benefit	$ 25	$ 25	$ 22
Valuation allowance adjustments	0	0	12
Stock-based compensation	1	(3)	0
Deferred tax impact of U.S. tax reform	112	0	0
Amortization of investment tax credit	(3)	(3)	(3)
Other	(2)	(2)	(3)
Total increase (decrease)	133	17	28
Total income tax from continuing operations	$ 375	$ 257	$ 239
Effective income tax rate	54.30%	37.50%	39.60%
Taxes, other than income
Domestic property and other	$ 65	$ 62	$ 57
Total	65	62	57
LG And E And KU Energy LLC [Member] | Tax Cuts And Jobs Act [Member]
Income Tax Expense (Benefit)
Deferred Income Tax Expense (Benefit) Tax Rate Change	108
Deferred Income Tax Expense (Benefit) Expiring Tax Credit	4
Tax expense (benefit) of operating loss carryforwards [Abstract]
Total income tax from continuing operations	112
Income tax expense (benefit) from continuing operations [Abstract]
Total income tax from continuing operations	112
Increase (decrease) due to:
Total income tax from continuing operations	112
Deferred Income Tax Expense Benefit Tax Reform	112
Louisville Gas And Electric Co [Member]
Income Tax Expense (Benefit)
Current - Federal	0	(22)	(15)
Current - State	5	1	3
Total Current Expense (Benefit)	5	(21)	(12)
Deferred - Federal	112	134	190
Deferred - State	14	18	13
Total Deferred Expense (Benefit), excluding operating loss carry forwards	126	152	203
Amortization of investment tax credit - Federal	(1)	(1)	(1)
Tax expense (benefit) of operating loss carryforwards [Abstract]
Deferred - Federal	1	(4)	(76)
Total Tax Expense (Benefit) of Operating Loss Carryforwards	1	(4)	(76)
Total income tax from continuing operations	131	126	114
Income tax expense (benefit) from continuing operations [Abstract]
Total income tax expense - Federal	112	107	98
Total income tax expense - State	19	19	16
Total income tax from continuing operations	131	126	114
Reconciliation of Income Tax Expense
Federal income tax on Income (Loss) from Continuing Operations Before Income Taxes at statutory tax rate - 35%	$ 120	$ 115	$ 105
Federal statutory rate	35.00%	35.00%	35.00%
Increase (decrease) due to:
State income taxes, net of federal income tax benefit	$ 13	$ 12	$ 11
Amortization of investment tax credit	(1)	(1)	(1)
Other	(1)	0	(1)
Total increase (decrease)	11	11	9
Total income tax from continuing operations	$ 131	$ 126	$ 114
Effective income tax rate	38.10%	38.30%	38.10%
Taxes, other than income
Domestic property and other	$ 33	$ 32	$ 28
Total	33	32	28
Louisville Gas And Electric Co [Member] | Tax Cuts And Jobs Act [Member]
Tax expense (benefit) of operating loss carryforwards [Abstract]
Total income tax from continuing operations	0
Income tax expense (benefit) from continuing operations [Abstract]
Total income tax from continuing operations	0
Increase (decrease) due to:
Total income tax from continuing operations	0
Kentucky Utilities Co [Member]
Income Tax Expense (Benefit)
Current - Federal	0	31	(21)
Current - State	7	5	1
Total Current Expense (Benefit)	7	36	(20)
Deferred - Federal	138	131	240
Deferred - State	16	19	19
Total Deferred Expense (Benefit), excluding operating loss carry forwards	154	150	259
Amortization of investment tax credit - Federal	(2)	(2)	(2)
Tax expense (benefit) of operating loss carryforwards [Abstract]
Deferred - Federal	0	(21)	(97)
Total Tax Expense (Benefit) of Operating Loss Carryforwards	0	(21)	(97)
Total income tax from continuing operations	159	163	140
Income tax expense (benefit) from continuing operations [Abstract]
Total income tax expense - Federal	136	139	120
Total income tax expense - State	23	24	20
Total income tax from continuing operations	159	163	140
Other comprehensive income	1	(1)	(1)
Reconciliation of Income Tax Expense
Federal income tax on Income (Loss) from Continuing Operations Before Income Taxes at statutory tax rate - 35%	$ 146	$ 150	$ 131
Federal statutory rate	35.00%	35.00%	35.00%
Increase (decrease) due to:
State income taxes, net of federal income tax benefit	$ 15	$ 16	$ 13
Amortization of investment tax credit	(2)	(2)	(2)
Other	0	(1)	(2)
Total increase (decrease)	13	13	9
Total income tax from continuing operations	$ 159	$ 163	$ 140
Effective income tax rate	38.00%	38.10%	37.40%
Taxes, other than income
Domestic property and other	$ 32	$ 30	$ 29
Total	32	$ 30	$ 29
Kentucky Utilities Co [Member] | Tax Cuts And Jobs Act [Member]
Tax expense (benefit) of operating loss carryforwards [Abstract]
Total income tax from continuing operations	0
Income tax expense (benefit) from continuing operations [Abstract]
Total income tax from continuing operations	0
Increase (decrease) due to:
Total income tax from continuing operations	$ 0