Segment and Related Information (Income Statement and Balance Sheet Data) (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 ($) Integer		Dec. 31, 2017 USD ($)		Dec. 31, 2016 USD ($)
Income Statement Data
Operating Revenues from external customers		$ 1,939	$ 1,872	$ 1,848	$ 2,126	$ 1,926	$ 1,845	$ 1,725	$ 1,951	$ 7,785		$ 7,447		$ 7,517
Depreciation										1,094		1,008		926
Amortization										78		97		80
Unrealized (gains) losses on derivatives and other hedging activities										(186)		178		19
Interest Expense										963		901		888
Income Before Income Taxes										2,285		1,912		2,550
Income Taxes										458		784		648
Deferred income taxes and investment tax credits										355		707		560
Net income		415	445	515	452	78	355	292	403	1,827		1,128		1,902
Cash Flow Data
Expenditures for long-lived assets										3,268		3,171		2,957
Balance Sheet Data
Total Assets		43,396				41,479				$ 43,396		41,479
Segment Information (Numeric) [Abstract]
Number of reportable segments | Integer										3
U.K. Regulated [Member]
Income Statement Data
Operating Revenues from external customers										$ 2,268		2,091		2,207
Depreciation										247		230		233
Amortization										34		34		16
Unrealized (gains) losses on derivatives and other hedging activities										(190)		166		13
Interest Expense										413		397		402
Income Before Income Taxes										1,339		804		1,479
Income Taxes										225		152		233
Deferred income taxes and investment tax credits										118		66		31
Net income										1,114		652		1,246
Cash Flow Data
Expenditures for long-lived assets										954		1,015		1,031
Balance Sheet Data
Total Assets		16,700				16,813				16,700		16,813
Segment Information (Numeric) [Abstract]
Net property, plant and equipment not subject to accounting for the effects of certain types of regulation		12,400				12,500				12,400		12,500
Kentucky Regulated [Member]
Income Statement Data
Operating Revenues from external customers										3,214		3,156		3,141
Depreciation										475		439		404
Amortization										18		24		29
Unrealized (gains) losses on derivatives and other hedging activities										6		6		6
Interest Expense										274		261		260
Income Before Income Taxes										531		645		640
Income Taxes										120		359		242
Deferred income taxes and investment tax credits										94		294		291
Net income										411		286		398
Cash Flow Data
Expenditures for long-lived assets										1,117		892		791
Balance Sheet Data
Total Assets		15,078				14,468				15,078		14,468
Pennsylvania Regulated [Member]
Income Statement Data
Operating Revenues from external customers										2,277		2,195		2,156
Depreciation										352		309		253
Amortization										22		33		32
Interest Expense										159		142		129
Income Before Income Taxes										567		575		550
Income Taxes										136		216		212
Deferred income taxes and investment tax credits										125		257		221
Net income										431		359		338
Cash Flow Data
Expenditures for long-lived assets										1,196		1,254		1,134
Balance Sheet Data
Total Assets		11,257				10,082				11,257		10,082
Corporate And Other [Member]
Income Statement Data
Operating Revenues from external customers										26		5		13
Depreciation										20		30		36
Amortization										4		6		3
Unrealized (gains) losses on derivatives and other hedging activities										(2)		6		0
Interest Expense										117		101		97
Income Before Income Taxes										(152)		(112)		(119)
Income Taxes										(23)		57		(39)
Deferred income taxes and investment tax credits										18		90		17
Net income										(129)		(169)		(80)
Cash Flow Data
Expenditures for long-lived assets										1		10		1
Balance Sheet Data
Total Assets		361				116				361		116
PPL Electric Utilities Corp [Member]
Income Statement Data
Operating Revenues from external customers		573	548	517	639	575	547	500	573	2,277		2,195		2,156
Depreciation										352		309		253
Amortization										22		33		32
Interest Expense										159		142		129
Income Before Income Taxes										566		575		552
Income Taxes										136		213		212
Deferred income taxes and investment tax credits										125		258		221
Net income		96	$ 111	$ 75	$ 148	111	$ 95	$ 77	$ 79	430	[1]	362	[1]	340	[1]
Balance Sheet Data
Total Assets		11,243				10,082				$ 11,243		10,082
Segment Information (Numeric) [Abstract]
Number of operating segments | Integer										2
Number of reportable segments | Integer										1
LG And E And KU Energy LLC [Member]
Income Statement Data
Operating Revenues from external customers										$ 3,214		3,156		3,141
Depreciation										475		439		404
Amortization										18		24		29
Interest Expense										206		197		197
Income Before Income Taxes										574		691		686
Income Taxes										129		375		257
Deferred income taxes and investment tax credits										94		294		291
Net income										445		316		429
Balance Sheet Data
Total Assets		15,412				14,802				$ 15,412		14,802
Segment Information (Numeric) [Abstract]
Number of operating segments | Integer										1
Number of reportable segments | Integer										1
Louisville Gas And Electric Co [Member]
Income Statement Data
Operating Revenues from external customers										$ 1,496		1,453		1,430
Depreciation										195		183		170
Amortization										14		14		14
Interest Expense										76		71		71
Income Before Income Taxes										297		344		329
Income Taxes										64		131		126
Deferred income taxes and investment tax credits										60		126		147
Net income	[2]									233		213		203
Balance Sheet Data
Total Assets		6,883				6,559				$ 6,883		6,559
Segment Information (Numeric) [Abstract]
Number of operating segments | Integer										1
Number of reportable segments | Integer										1
Kentucky Utilities Co [Member]
Income Statement Data
Operating Revenues from external customers										$ 1,760		1,744		1,749
Depreciation										279		255		234
Amortization										3		9		14
Interest Expense										100		96		96
Income Before Income Taxes										362		418		428
Income Taxes										76		159		163
Deferred income taxes and investment tax credits										48		152		126
Net income	[3]									286		259		$ 265
Balance Sheet Data
Total Assets		$ 8,540				$ 8,254				$ 8,540		$ 8,254
Segment Information (Numeric) [Abstract]
Number of operating segments | Integer										1
Number of reportable segments | Integer										1

[1] Net income equals comprehensive income.

[2] Net income equals comprehensive income.

[3] Net income approximates comprehensive income.