Accumulated Other Comprehensive Income (Loss) (After-tax Changes by Component) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of year	$ (4,358)	$ (3,964)	$ (3,422)
Amounts arising during the year	(94)	(496)	(606)
Reclassifications from AOCI	232	102	115
Net OCI during the year	138	(394)	(491)
Adoption of reclassification of certain tax effects from AOCI guidance cumulative effect adjustment			(51)
Balance at end of year	(4,220)	(4,358)	(3,964)
Foreign Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of year	(1,425)	(1,533)	(1,089)
Amounts arising during the year	267	108	(444)
Reclassifications from AOCI	0	0	0
Net OCI during the year	267	108	(444)
Adoption of reclassification of certain tax effects from AOCI guidance cumulative effect adjustment			0
Balance at end of year	(1,158)	(1,425)	(1,533)
Qualifying Derivatives [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of year	(5)	(7)	(13)
Amounts arising during the year	(19)	(11)	36
Reclassifications from AOCI	24	13	(29)
Net OCI during the year	5	2	7
Adoption of reclassification of certain tax effects from AOCI guidance cumulative effect adjustment			(1)
Balance at end of year	0	(5)	(7)
Prior Service Costs [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of year	(18)	(19)	(7)
Amounts arising during the year	(1)	(1)	(11)
Reclassifications from AOCI	3	2	2
Net OCI during the year	2	1	(9)
Adoption of reclassification of certain tax effects from AOCI guidance cumulative effect adjustment			(3)
Balance at end of year	(16)	(18)	(19)
Defined Benefit Plans Actuarial Gain (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of year	(2,910)	(2,405)	(2,313)
Amounts arising during the year	(341)	(592)	(187)
Reclassifications from AOCI	205	87	142
Net OCI during the year	(136)	(505)	(45)
Adoption of reclassification of certain tax effects from AOCI guidance cumulative effect adjustment			(47)
Balance at end of year	(3,046)	(2,910)	(2,405)
Accumulated Defined Benefit Plans Net [Member] | WPD [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at end of year	2,900
LG And E And KU Energy LLC [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of year	(93)	(89)	(88)
Amounts arising during the year	(8)	(7)	7
Reclassifications from AOCI	15	3	10
Net OCI during the year	7	(4)	17
Adoption of reclassification of certain tax effects from AOCI guidance cumulative effect adjustment			(18)
Balance at end of year	(86)	(93)	(89)
LG And E And KU Energy LLC [Member] | Prior Service Costs [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of year	(9)	(9)	(9)
Amounts arising during the year	(1)	(1)	0
Reclassifications from AOCI	2	1	2
Net OCI during the year	1	0	2
Adoption of reclassification of certain tax effects from AOCI guidance cumulative effect adjustment			(2)
Balance at end of year	(8)	(9)	(9)
LG And E And KU Energy LLC [Member] | Defined Benefit Plans Actuarial Gain (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of year	(84)	(80)	(79)
Amounts arising during the year	(7)	(6)	7
Reclassifications from AOCI	13	2	8
Net OCI during the year	6	(4)	15
Adoption of reclassification of certain tax effects from AOCI guidance cumulative effect adjustment			(16)
Balance at end of year	$ (78)	$ (84)	$ (80)