Income Taxes - Tax Reform (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Tax Reform [Line Items]
Income Tax Expense (Benefit)	$ 103	$ 116	$ 362	$ 321
Tax Cuts And Jobs Act [Member] | Adjustments Per 2017 Tax Return [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	0		0
Income Tax Expense (Benefit)	321		321
Tax Cuts And Jobs Act [Member] | Adjustments Per 2017 Tax Provision [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	0		0
Income Tax Expense (Benefit)	321		321
Tax Cuts And Jobs Act [Member] | September 30, 2018 Adjustment [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	0		0
Income Tax Expense (Benefit)	0		0
Tax Cuts And Jobs Act [Member] | Deemed Dividend [Member] | Adjustments Per 2017 Tax Return [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	397		397
Income Tax Expense (Benefit)	139		139
Tax Cuts And Jobs Act [Member] | Deemed Dividend [Member] | Adjustments Per 2017 Tax Provision [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	462		462
Income Tax Expense (Benefit)	161		161
Tax Cuts And Jobs Act [Member] | Deemed Dividend [Member] | September 30, 2018 Adjustment [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	(65)		(65)
Income Tax Expense (Benefit)	(22)		(22)
Tax Cuts And Jobs Act [Member] | Bonus Depreciation [Member] | Adjustments Per 2017 Tax Return [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	(67)		(67)
Tax Cuts And Jobs Act [Member] | Bonus Depreciation [Member] | Adjustments Per 2017 Tax Provision [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	0		0
Tax Cuts And Jobs Act [Member] | Bonus Depreciation [Member] | September 30, 2018 Adjustment [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	(67)		(67)
Tax Cuts And Jobs Act [Member] | Consolidated Federal Net Operating Losses Due To The TCJA [Member] | Adjustments Per 2017 Tax Return [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	(330)		(330)
Tax Cuts And Jobs Act [Member] | Consolidated Federal Net Operating Losses Due To The TCJA [Member] | Adjustments Per 2017 Tax Provision [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	(462)		(462)
Tax Cuts And Jobs Act [Member] | Consolidated Federal Net Operating Losses Due To The TCJA [Member] | September 30, 2018 Adjustment [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	132		132
Tax Cuts And Jobs Act [Member] | Foreign Tax Credit [Member] | Adjustments Per 2017 Tax Return [Member]
Tax Reform [Line Items]
Income Tax Expense (Benefit)	(157)		(157)
Tax Cuts And Jobs Act [Member] | Foreign Tax Credit [Member] | Adjustments Per 2017 Tax Provision [Member]
Tax Reform [Line Items]
Income Tax Expense (Benefit)	(205)		(205)
Tax Cuts And Jobs Act [Member] | Foreign Tax Credit [Member] | September 30, 2018 Adjustment [Member]
Tax Reform [Line Items]
Income Tax Expense (Benefit)	48		48
Tax Cuts And Jobs Act [Member] | Valuation Of Foreign Tax Credit Carryforward [Member] | Adjustments Per 2017 Tax Return [Member]
Tax Reform [Line Items]
Income Tax Expense (Benefit)	110		110
Tax Cuts And Jobs Act [Member] | Valuation Of Foreign Tax Credit Carryforward [Member] | Adjustments Per 2017 Tax Provision [Member]
Tax Reform [Line Items]
Income Tax Expense (Benefit)	145		145
Tax Cuts And Jobs Act [Member] | Valuation Of Foreign Tax Credit Carryforward [Member] | September 30, 2018 Adjustment [Member]
Tax Reform [Line Items]
Income Tax Expense (Benefit)	(35)		(35)
Tax Cuts And Jobs Act [Member] | Reduction In U.S. Federal Income Tax Rate [Member] | Adjustments Per 2017 Tax Return [Member]
Tax Reform [Line Items]
Income Tax Expense (Benefit)	229		229
Tax Cuts And Jobs Act [Member] | Reduction In U.S. Federal Income Tax Rate [Member] | Adjustments Per 2017 Tax Provision [Member]
Tax Reform [Line Items]
Income Tax Expense (Benefit)	220		220
Tax Cuts And Jobs Act [Member] | Reduction In U.S. Federal Income Tax Rate [Member] | September 30, 2018 Adjustment [Member]
Tax Reform [Line Items]
Income Tax Expense (Benefit)	9		9
PPL Electric [Member] | Tax Cuts And Jobs Act [Member] | Adjustments Per 2017 Tax Return [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	(107)		(107)
PPL Electric [Member] | Tax Cuts And Jobs Act [Member] | Adjustments Per 2017 Tax Provision [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	(105)		(105)
PPL Electric [Member] | Tax Cuts And Jobs Act [Member] | September 30, 2018 Adjustment [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	(2)		(2)
PPL Electric [Member] | Tax Cuts And Jobs Act [Member] | Bonus Depreciation [Member] | Adjustments Per 2017 Tax Return [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	(39)		(39)
PPL Electric [Member] | Tax Cuts And Jobs Act [Member] | Bonus Depreciation [Member] | Adjustments Per 2017 Tax Provision [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	0		0
PPL Electric [Member] | Tax Cuts And Jobs Act [Member] | Bonus Depreciation [Member] | September 30, 2018 Adjustment [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	(39)		(39)
PPL Electric [Member] | Tax Cuts And Jobs Act [Member] | Consolidated Federal Net Operating Losses Due To The TCJA [Member] | Adjustments Per 2017 Tax Return [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	(68)		(68)
PPL Electric [Member] | Tax Cuts And Jobs Act [Member] | Consolidated Federal Net Operating Losses Due To The TCJA [Member] | Adjustments Per 2017 Tax Provision [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	(105)		(105)
PPL Electric [Member] | Tax Cuts And Jobs Act [Member] | Consolidated Federal Net Operating Losses Due To The TCJA [Member] | September 30, 2018 Adjustment [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	37		37
PPL Electric [Member] | Tax Cuts And Jobs Act [Member] | Reduction In U.S. Federal Income Tax Rate [Member] | Adjustments Per 2017 Tax Return [Member]
Tax Reform [Line Items]
Income Tax Expense (Benefit)	(13)		(13)
PPL Electric [Member] | Tax Cuts And Jobs Act [Member] | Reduction In U.S. Federal Income Tax Rate [Member] | Adjustments Per 2017 Tax Provision [Member]
Tax Reform [Line Items]
Income Tax Expense (Benefit)	(13)		(13)
PPL Electric [Member] | Tax Cuts And Jobs Act [Member] | Reduction In U.S. Federal Income Tax Rate [Member] | September 30, 2018 Adjustment [Member]
Tax Reform [Line Items]
Income Tax Expense (Benefit)	0		0
LG And E And KU Energy LLC [Member]
Tax Reform [Line Items]
Income Tax Expense (Benefit)	32	79	102	195
LG And E And KU Energy LLC [Member] | Tax Cuts And Jobs Act [Member] | Adjustments Per 2017 Tax Return [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	(60)		(60)
LG And E And KU Energy LLC [Member] | Tax Cuts And Jobs Act [Member] | Adjustments Per 2017 Tax Provision [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	(45)		(45)
LG And E And KU Energy LLC [Member] | Tax Cuts And Jobs Act [Member] | September 30, 2018 Adjustment [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	(15)		(15)
LG And E And KU Energy LLC [Member] | Tax Cuts And Jobs Act [Member] | Bonus Depreciation [Member] | Adjustments Per 2017 Tax Return [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	(28)		(28)
LG And E And KU Energy LLC [Member] | Tax Cuts And Jobs Act [Member] | Bonus Depreciation [Member] | Adjustments Per 2017 Tax Provision [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	0		0
LG And E And KU Energy LLC [Member] | Tax Cuts And Jobs Act [Member] | Bonus Depreciation [Member] | September 30, 2018 Adjustment [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	(28)		(28)
LG And E And KU Energy LLC [Member] | Tax Cuts And Jobs Act [Member] | Consolidated Federal Net Operating Losses Due To The TCJA [Member] | Adjustments Per 2017 Tax Return [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	(32)		(32)
LG And E And KU Energy LLC [Member] | Tax Cuts And Jobs Act [Member] | Consolidated Federal Net Operating Losses Due To The TCJA [Member] | Adjustments Per 2017 Tax Provision [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	(45)		(45)
LG And E And KU Energy LLC [Member] | Tax Cuts And Jobs Act [Member] | Consolidated Federal Net Operating Losses Due To The TCJA [Member] | September 30, 2018 Adjustment [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	13		13
LG And E And KU Energy LLC [Member] | Tax Cuts And Jobs Act [Member] | Reduction In U.S. Federal Income Tax Rate [Member] | Adjustments Per 2017 Tax Return [Member]
Tax Reform [Line Items]
Income Tax Expense (Benefit)	110		110
LG And E And KU Energy LLC [Member] | Tax Cuts And Jobs Act [Member] | Reduction In U.S. Federal Income Tax Rate [Member] | Adjustments Per 2017 Tax Provision [Member]
Tax Reform [Line Items]
Income Tax Expense (Benefit)	112		112
LG And E And KU Energy LLC [Member] | Tax Cuts And Jobs Act [Member] | Reduction In U.S. Federal Income Tax Rate [Member] | September 30, 2018 Adjustment [Member]
Tax Reform [Line Items]
Income Tax Expense (Benefit)	(2)		(2)
Louisville Gas And Electric Co [Member]
Tax Reform [Line Items]
Income Tax Expense (Benefit)	18	39	51	99
Louisville Gas And Electric Co [Member] | Tax Cuts And Jobs Act [Member] | Adjustments Per 2017 Tax Return [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	0		0
Louisville Gas And Electric Co [Member] | Tax Cuts And Jobs Act [Member] | Adjustments Per 2017 Tax Provision [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	0		0
Louisville Gas And Electric Co [Member] | Tax Cuts And Jobs Act [Member] | September 30, 2018 Adjustment [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	0		0
Louisville Gas And Electric Co [Member] | Tax Cuts And Jobs Act [Member] | Bonus Depreciation [Member] | Adjustments Per 2017 Tax Return [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	(17)		(17)
Louisville Gas And Electric Co [Member] | Tax Cuts And Jobs Act [Member] | Bonus Depreciation [Member] | Adjustments Per 2017 Tax Provision [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	0		0
Louisville Gas And Electric Co [Member] | Tax Cuts And Jobs Act [Member] | Bonus Depreciation [Member] | September 30, 2018 Adjustment [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	(17)		(17)
Louisville Gas And Electric Co [Member] | Tax Cuts And Jobs Act [Member] | Consolidated Federal Net Operating Losses Due To The TCJA [Member] | Adjustments Per 2017 Tax Return [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	17		17
Louisville Gas And Electric Co [Member] | Tax Cuts And Jobs Act [Member] | Consolidated Federal Net Operating Losses Due To The TCJA [Member] | Adjustments Per 2017 Tax Provision [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	0		0
Louisville Gas And Electric Co [Member] | Tax Cuts And Jobs Act [Member] | Consolidated Federal Net Operating Losses Due To The TCJA [Member] | September 30, 2018 Adjustment [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	17		17
Kentucky Utilities Co [Member]
Tax Reform [Line Items]
Income Tax Expense (Benefit)	21	$ 47	59	$ 120
Kentucky Utilities Co [Member] | Tax Cuts And Jobs Act [Member] | Adjustments Per 2017 Tax Return [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	0		0
Kentucky Utilities Co [Member] | Tax Cuts And Jobs Act [Member] | Adjustments Per 2017 Tax Provision [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	0		0
Kentucky Utilities Co [Member] | Tax Cuts And Jobs Act [Member] | September 30, 2018 Adjustment [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	0		0
Kentucky Utilities Co [Member] | Tax Cuts And Jobs Act [Member] | Bonus Depreciation [Member] | Adjustments Per 2017 Tax Return [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	(11)		(11)
Kentucky Utilities Co [Member] | Tax Cuts And Jobs Act [Member] | Bonus Depreciation [Member] | Adjustments Per 2017 Tax Provision [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	0		0
Kentucky Utilities Co [Member] | Tax Cuts And Jobs Act [Member] | Bonus Depreciation [Member] | September 30, 2018 Adjustment [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	(11)		(11)
Kentucky Utilities Co [Member] | Tax Cuts And Jobs Act [Member] | Consolidated Federal Net Operating Losses Due To The TCJA [Member] | Adjustments Per 2017 Tax Return [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	11		11
Kentucky Utilities Co [Member] | Tax Cuts And Jobs Act [Member] | Consolidated Federal Net Operating Losses Due To The TCJA [Member] | Adjustments Per 2017 Tax Provision [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	0		0
Kentucky Utilities Co [Member] | Tax Cuts And Jobs Act [Member] | Consolidated Federal Net Operating Losses Due To The TCJA [Member] | September 30, 2018 Adjustment [Member]
Tax Reform [Line Items]
Taxable Income (Loss)	$ 11		$ 11