Summary of Significant Accounting Policies (Details) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2019 USD ($) Integer	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Utility Revenue (Details) [Abstract]
Operating Revenues	$ 1,954	$ 1,933	$ 1,803	$ 2,079	$ 1,939	$ 1,872	$ 1,848	$ 2,126	$ 7,769	$ 7,785	$ 7,447
Restricted Cash and Cash Equivalents [Abstract]
Cash and cash equivalents	815				621				815	621
Restricted cash - current	3				3				3	3
Restricted Cash - noncurrent	18				19				18	19
Total Cash, Cash Equivalents and Restricted Cash	836				643				836	643	511	$ 372
Property, Plant and Equipment (Numeric) [Abstract]
Interest costs, capitalized during the period									$ 10	15	$ 11
Discount Rate Change For United Kingdom Pension Plans Numeric [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	332				303				$ 332	303
Fuel [Member]
Fuel, Materials and Supplies (Details) [Abstract]
Fuel, materials and supplies on the Balance Sheet	106				98				106	98
Natural Gas Stored Underground [Member]
Fuel, Materials and Supplies (Details) [Abstract]
Fuel, materials and supplies on the Balance Sheet	35				41				35	41
Material And Supplies [Member]
Fuel, Materials and Supplies (Details) [Abstract]
Fuel, materials and supplies on the Balance Sheet	191				164				$ 191	$ 164
Regulated Operations [Member] | Utility Plant [Member]
Depreciation (Details) [Abstract]
Weighted-average rates									2.84%	2.77%	2.65%
Allowance For Doubtful Accounts [Member]
Allowance for Doubtful Accounts (Details) [Roll Forward]
Balance at beginning of period				56				51	$ 56	$ 51	$ 54
Additions charged to income									37	41	28
Additions charged to other accounts									3	3	(1)
Deductions									38	39	30
Balance at end of period	58				56				$ 58	56	51
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
PPL Electric Utilities Corp [Member]
Utility Revenue (Details) [Abstract]
Operating Revenues	602	$ 590	$ 521	645	573	$ 548	$ 517	639	$ 2,358	2,277	2,195
Restricted Cash and Cash Equivalents [Abstract]
Cash and cash equivalents	262				267				262	267
Restricted cash - current	2				2				2	2
Restricted Cash - noncurrent	0				0				0	0
Total Cash, Cash Equivalents and Restricted Cash	264				269				$ 264	269	$ 51	15
Property, Plant and Equipment (Numeric) [Abstract]
Regulatory Asset Amortization Period									5 years
Discount Rate Change For United Kingdom Pension Plans Numeric [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)	3				19				$ 3	$ 19
PPL Electric Utilities Corp [Member] | Regulated Operations [Member] | Utility Plant [Member]
Depreciation (Details) [Abstract]
Weighted-average rates									3.05%	3.01%	2.86%
PPL Electric Utilities Corp [Member] | Allowance For Doubtful Accounts [Member]
Allowance for Doubtful Accounts (Details) [Roll Forward]
Balance at beginning of period				27				24	$ 27	$ 24	$ 28
Additions charged to income									26	29	18
Additions charged to other accounts									0	0	0
Deductions									25	26	22
Balance at end of period	28				27				28	27	24
LG And E And KU Energy LLC [Member]
Utility Revenue (Details) [Abstract]
Operating Revenues									3,206	3,214	3,156
Restricted Cash and Cash Equivalents [Abstract]
Cash and cash equivalents	27				24				$ 27	24	$ 30	13
Discount Rate Change For United Kingdom Pension Plans Numeric [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)	(8)				(16)				$ (8)	(16)
Fuel, Materials and Supplies (Details) [Abstract]
Fuel, materials and supplies on the Balance Sheet	250				248				250	248
LG And E And KU Energy LLC [Member] | Fuel [Member]
Fuel, Materials and Supplies (Details) [Abstract]
Fuel, materials and supplies on the Balance Sheet	106				98				106	98
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	35				41				35	41
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				109				$ 109	$ 109
LG And E And KU Energy LLC [Member] | Regulated Operations [Member] | Utility Plant [Member]
Depreciation (Details) [Abstract]
Weighted-average rates									3.96%	3.69%	3.64%
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				27				25	$ 27	$ 25	$ 24
Additions charged to income									8	10	8
Additions charged to other accounts									3	3	(1)
Deductions									10	11	6
Balance at end of period	28				27				28	27	25
Louisville Gas And Electric Co [Member]
Utility Revenue (Details) [Abstract]
Operating Revenues									1,500	1,496	1,453
Restricted Cash and Cash Equivalents [Abstract]
Cash and cash equivalents	15				10				$ 15	10	$ 15	5
Discount Rate Change For United Kingdom Pension Plans Numeric [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)	(4)				0				$ (4)	0
Fuel, Materials and Supplies (Details) [Abstract]
Fuel, materials and supplies on the Balance Sheet	122				127				122	127
Louisville Gas And Electric Co [Member] | Fuel [Member]
Fuel, Materials and Supplies (Details) [Abstract]
Fuel, materials and supplies on the Balance Sheet	43				42				43	42
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	35				41				35	41
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				44				$ 44	$ 44
Louisville Gas And Electric Co [Member] | Regulated Operations [Member] | Utility Plant [Member]
Depreciation (Details) [Abstract]
Weighted-average rates									3.87%	3.63%	3.63%
Louisville Gas And Electric Co [Member] | Allowance For Doubtful Accounts [Member]
Allowance for Doubtful Accounts (Details) [Roll Forward]
Balance at beginning of period				1				1	$ 1	$ 1	$ 2
Additions charged to income									2	4	2
Additions charged to other accounts									2	1	(1)
Deductions									4	5	2
Balance at end of period	1				1				1	1	1
Kentucky Utilities Co [Member]
Utility Revenue (Details) [Abstract]
Operating Revenues									1,740	1,760	1,744
Restricted Cash and Cash Equivalents [Abstract]
Cash and cash equivalents	12				14				$ 12	14	$ 15	$ 7
Discount Rate Change For United Kingdom Pension Plans Numeric [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)	(6)				(5)				$ (6)	(5)
Fuel, Materials and Supplies (Details) [Abstract]
Fuel, materials and supplies on the Balance Sheet	128				121				128	121
Kentucky Utilities Co [Member] | Fuel [Member]
Fuel, Materials and Supplies (Details) [Abstract]
Fuel, materials and supplies on the Balance Sheet	63				56				63	56
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				65				$ 65	$ 65
Kentucky Utilities Co [Member] | Regulated Operations [Member] | Utility Plant [Member]
Depreciation (Details) [Abstract]
Weighted-average rates									4.02%	3.74%	3.66%
Kentucky Utilities Co [Member] | Allowance For Doubtful Accounts [Member]
Allowance for Doubtful Accounts (Details) [Roll Forward]
Balance at beginning of period				$ 2				$ 1	$ 2	$ 1	$ 2
Additions charged to income									4	5	4
Additions charged to other accounts									1	2	(1)
Deductions									6	6	4
Balance at end of period	$ 1				$ 2				$ 1	$ 2	$ 1