Summary of Significant Accounting Policies (Details) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2018 USD ($) Integer MW	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Utility Revenue (Details) [Abstract]
Domestic electric and gas revenue									$ 5,491	$ 5,351	$ 5,297
U.K. operating revenues									2,268	2,091	2,207
Domestic - other									26	5	13
Operating Revenues	$ 1,939	$ 1,872	$ 1,848	$ 2,126	$ 1,926	$ 1,845	$ 1,725	$ 1,951	7,785	7,447	7,517
Property, Plant and Equipment (Numeric) [Abstract]
Interest costs, capitalized during the period									$ 15	11	$ 11
Defined Benefits [Abstract]
Percentage in excess of gains and losses equal to the plan's projected benefit obligation to use accelerated amortization									30.00%
Minimum percentage of gains and losses under the accelerated method that are amortized on a straight line basis									10.00%
Maximum percentage of gains and losses under the accelerated that are amortized on a straight line basis									30.00%
Income Taxes [Abstract]
Minimum percentage to be attained of likelihood of uncertain tax position being realized									50.00%
Fuel, Materials and Supplies (Details) [Abstract]
Fuel, materials and supplies on the Balance Sheet	303				320				$ 303	320
Fuel [Member]
Fuel, Materials and Supplies (Details) [Abstract]
Fuel, materials and supplies on the Balance Sheet	98				107				98	107
Natural Gas Stored Underground [Member]
Fuel, Materials and Supplies (Details) [Abstract]
Fuel, materials and supplies on the Balance Sheet	41				43				41	43
Material And Supplies [Member]
Fuel, Materials and Supplies (Details) [Abstract]
Fuel, materials and supplies on the Balance Sheet	164				170				$ 164	$ 170
Regulated Operations [Member] | Utility Plant [Member]
Depreciation (Details) [Abstract]
Weighted-average rates									2.77%	2.65%	2.73%
Allowance For Doubtful Accounts [Member]
Allowance for Doubtful Accounts (Details) [Roll Forward]
Balance at beginning of period				51				54	$ 51	$ 54	$ 41
Additions charged to income									41	28	44
Additions charged to other accounts									3	(1)	0
Deductions									39	30	31
Balance at end of period	56				51				$ 56	51	54
WPD [Member]
Summary of Significant Accounting Policies [Line Items]
Period of lag in reporting results for WPD (in months) | Integer									1
Revenue Recognition (Numeric) [Abstract]
Number of regulatory years later future demand revenue is affected									2 years
Percentage WPD's distribution network operators are able to retain of any under-spends									70.00%
Percentage WPD's distribution network operators bear of any over-spends									70.00%
Period of lag between incentives and penalties are reflected in customers' rates									2 years
Refunded/recovered period of lag for recovery of over and under-recovered amounts arising from 2014/15 onwards									2 years
Previous refunded/recovered period of lag for recovery of over and under-recovered amounts									1 year
LGE [Member] | Ohio Valley Electric Corporation [Member]
Investments in Equity Securities [Abstract]
Number of other electric utilities that are equity owners | Integer									10
Number of other companies power is supplied to | Integer									11
Ownership percentage									5.63%
Generation capacity in terms of ownership percentage (in MW) | MW									120
KU [Member] | Ohio Valley Electric Corporation [Member]
Investments in Equity Securities [Abstract]
Number of other electric utilities that are equity owners | Integer									10
Number of other companies power is supplied to | Integer									11
Ownership percentage									2.50%
Generation capacity in terms of ownership percentage (in MW) | MW									53
PPL Electric Utilities Corp [Member]
Utility Revenue (Details) [Abstract]
Operating Revenues	573	$ 548	$ 517	639	575	$ 547	$ 500	573	$ 2,277	2,195	$ 2,156
Property, Plant and Equipment (Numeric) [Abstract]
Regulatory Asset Amortization Period									5 years
Defined Benefits [Abstract]
Percentage in excess of gains and losses equal to the plan's projected benefit obligation to use accelerated amortization									30.00%
Minimum percentage of gains and losses under the accelerated method that are amortized on a straight line basis									10.00%
Maximum percentage of gains and losses under the accelerated that are amortized on a straight line basis									30.00%
Income Taxes [Abstract]
Minimum percentage to be attained of likelihood of uncertain tax position being realized									50.00%
Intercompany tax receivables (payables)	19				61				$ 19	$ 61
PPL Electric Utilities Corp [Member] | Regulated Operations [Member] | Utility Plant [Member]
Depreciation (Details) [Abstract]
Weighted-average rates									3.01%	2.86%	2.63%
PPL Electric Utilities Corp [Member] | Allowance For Doubtful Accounts [Member]
Allowance for Doubtful Accounts (Details) [Roll Forward]
Balance at beginning of period				24				28	$ 24	$ 28	$ 16
Additions charged to income									29	18	35
Additions charged to other accounts									0	0	0
Deductions									26	22	23
Balance at end of period	27				24				27	24	28
LG And E And KU Energy LLC [Member]
Utility Revenue (Details) [Abstract]
Operating Revenues									$ 3,214	3,156	$ 3,141
Defined Benefits [Abstract]
Percentage in excess of gains and losses equal to the plan's projected benefit obligation to use accelerated amortization									30.00%
Minimum percentage of gains and losses under the accelerated method that are amortized on a straight line basis									10.00%
Maximum percentage of gains and losses under the accelerated that are amortized on a straight line basis									30.00%
Income Taxes [Abstract]
Minimum percentage to be attained of likelihood of uncertain tax position being realized									50.00%
Intercompany tax receivables (payables)	(16)				(23)				$ (16)	(23)
Fuel, Materials and Supplies (Details) [Abstract]
Fuel, materials and supplies on the Balance Sheet	248				254				248	254
LG And E And KU Energy LLC [Member] | Fuel [Member]
Fuel, Materials and Supplies (Details) [Abstract]
Fuel, materials and supplies on the Balance Sheet	98				107				98	107
LG And E And KU Energy LLC [Member] | Natural Gas Stored Underground [Member]
Fuel, Materials and Supplies (Details) [Abstract]
Fuel, materials and supplies on the Balance Sheet	41				43				41	43
LG And E And KU Energy LLC [Member] | Material And Supplies [Member]
Fuel, Materials and Supplies (Details) [Abstract]
Fuel, materials and supplies on the Balance Sheet	109				104				$ 109	$ 104
LG And E And KU Energy LLC [Member] | Regulated Operations [Member] | Utility Plant [Member]
Depreciation (Details) [Abstract]
Weighted-average rates									3.69%	3.64%	3.69%
LG And E And KU Energy LLC [Member] | Allowance For Doubtful Accounts [Member]
Allowance for Doubtful Accounts (Details) [Roll Forward]
Balance at beginning of period				25				24	$ 25	$ 24	$ 23
Additions charged to income									10	8	8
Additions charged to other accounts									3	(1)	0
Deductions									11	6	7
Balance at end of period	27				25				$ 27	25	24
LG And E And KU Energy LLC [Member] | LGE [Member] | Ohio Valley Electric Corporation [Member]
Investments in Equity Securities [Abstract]
Number of other electric utilities that are equity owners | Integer									10
Number of other companies power is supplied to | Integer									11
Ownership percentage									5.63%
Generation capacity in terms of ownership percentage (in MW) | MW									120
LG And E And KU Energy LLC [Member] | KU [Member] | Ohio Valley Electric Corporation [Member]
Investments in Equity Securities [Abstract]
Number of other electric utilities that are equity owners | Integer									10
Number of other companies power is supplied to | Integer									11
Ownership percentage									2.50%
Generation capacity in terms of ownership percentage (in MW) | MW									53
Louisville Gas And Electric Co [Member]
Utility Revenue (Details) [Abstract]
Operating Revenues									$ 1,496	1,453	$ 1,430
Defined Benefits [Abstract]
Percentage in excess of gains and losses equal to the plan's projected benefit obligation to use accelerated amortization									30.00%
Minimum percentage of gains and losses under the accelerated method that are amortized on a straight line basis									10.00%
Maximum percentage of gains and losses under the accelerated that are amortized on a straight line basis									30.00%
Income Taxes [Abstract]
Minimum percentage to be attained of likelihood of uncertain tax position being realized									50.00%
Intercompany tax receivables (payables)	0				0				$ 0	0
Fuel, Materials and Supplies (Details) [Abstract]
Fuel, materials and supplies on the Balance Sheet	127				131				127	131
Louisville Gas And Electric Co [Member] | Fuel [Member]
Fuel, Materials and Supplies (Details) [Abstract]
Fuel, materials and supplies on the Balance Sheet	42				45				42	45
Louisville Gas And Electric Co [Member] | Natural Gas Stored Underground [Member]
Fuel, Materials and Supplies (Details) [Abstract]
Fuel, materials and supplies on the Balance Sheet	41				43				41	43
Louisville Gas And Electric Co [Member] | Material And Supplies [Member]
Fuel, Materials and Supplies (Details) [Abstract]
Fuel, materials and supplies on the Balance Sheet	44				43				$ 44	$ 43
Louisville Gas And Electric Co [Member] | Regulated Operations [Member] | Utility Plant [Member]
Depreciation (Details) [Abstract]
Weighted-average rates									3.63%	3.63%	3.58%
Louisville Gas And Electric Co [Member] | Ohio Valley Electric Corporation [Member]
Investments in Equity Securities [Abstract]
Number of other electric utilities that are equity owners | Integer									10
Number of other companies power is supplied to | Integer									11
Ownership percentage									5.63%
Generation capacity in terms of ownership percentage (in MW) | MW									120
Louisville Gas And Electric Co [Member] | Allowance For Doubtful Accounts [Member]
Allowance for Doubtful Accounts (Details) [Roll Forward]
Balance at beginning of period				1				2	$ 1	$ 2	$ 1
Additions charged to income									4	2	2
Additions charged to other accounts									1	(1)	1
Deductions									5	2	2
Balance at end of period	1				1				1	1	2
Kentucky Utilities Co [Member]
Utility Revenue (Details) [Abstract]
Operating Revenues									$ 1,760	1,744	$ 1,749
Defined Benefits [Abstract]
Percentage in excess of gains and losses equal to the plan's projected benefit obligation to use accelerated amortization									30.00%
Minimum percentage of gains and losses under the accelerated method that are amortized on a straight line basis									10.00%
Maximum percentage of gains and losses under the accelerated that are amortized on a straight line basis									30.00%
Income Taxes [Abstract]
Minimum percentage to be attained of likelihood of uncertain tax position being realized									50.00%
Intercompany tax receivables (payables)	(5)				0				$ (5)	0
Fuel, Materials and Supplies (Details) [Abstract]
Fuel, materials and supplies on the Balance Sheet	121				123				121	123
Kentucky Utilities Co [Member] | Fuel [Member]
Fuel, Materials and Supplies (Details) [Abstract]
Fuel, materials and supplies on the Balance Sheet	56				62				56	62
Kentucky Utilities Co [Member] | Natural Gas Stored Underground [Member]
Fuel, Materials and Supplies (Details) [Abstract]
Fuel, materials and supplies on the Balance Sheet	0				0				0	0
Kentucky Utilities Co [Member] | Material And Supplies [Member]
Fuel, Materials and Supplies (Details) [Abstract]
Fuel, materials and supplies on the Balance Sheet	65				61				$ 65	$ 61
Kentucky Utilities Co [Member] | Regulated Operations [Member] | Utility Plant [Member]
Depreciation (Details) [Abstract]
Weighted-average rates									3.74%	3.66%	3.77%
Kentucky Utilities Co [Member] | Ohio Valley Electric Corporation [Member]
Investments in Equity Securities [Abstract]
Number of other electric utilities that are equity owners | Integer									10
Number of other companies power is supplied to | Integer									11
Ownership percentage									2.50%
Generation capacity in terms of ownership percentage (in MW) | MW									53
Kentucky Utilities Co [Member] | Allowance For Doubtful Accounts [Member]
Allowance for Doubtful Accounts (Details) [Roll Forward]
Balance at beginning of period				$ 1				$ 2	$ 1	$ 2	$ 2
Additions charged to income									5	4	4
Additions charged to other accounts									2	(1)	0
Deductions									6	4	4
Balance at end of period	$ 2				$ 1				$ 2	$ 1	$ 2