Accumulated Other Comprehensive Income (Loss) (After-tax Changes by Component) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of year	$ (124)	$ (157)	$ (4,220)
Amounts arising during the year	(40)	12	332
Reclassifications from AOCI	1	21	153
Net OCI during the year	(39)	33	4,063
Balance at end of year	(163)	(124)	(157)
Reclassification out of Accumulated Other Comprehensive Income (Loss) due to Sale of U.K, Utility Business
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassifications from AOCI			3,578
Foreign Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of year	0	0	(1,158)
Amounts arising during the year	0	0	372
Reclassifications from AOCI	0	0	0
Net OCI during the year	0	0	1,158
Balance at end of year	0	0	0
Foreign Currency Translation Adjustments [Member] | Reclassification out of Accumulated Other Comprehensive Income (Loss) due to Sale of U.K, Utility Business
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassifications from AOCI			786
Qualifying Derivatives [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of year	3	1	0
Amounts arising during the year	0	0	(39)
Reclassifications from AOCI	3	2	25
Net OCI during the year	3	2	1
Balance at end of year	6	3	1
Qualifying Derivatives [Member] | Reclassification out of Accumulated Other Comprehensive Income (Loss) due to Sale of U.K, Utility Business
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassifications from AOCI			15
Equity Investees AOCI [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of year	2	0	0
Amounts arising during the year	1	2	0
Reclassifications from AOCI	0	0	0
Net OCI during the year	1	2	0
Balance at end of year	3	2	0
Equity Investees AOCI [Member] | Reclassification out of Accumulated Other Comprehensive Income (Loss) due to Sale of U.K, Utility Business
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassifications from AOCI			0
Prior Service Costs [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of year	(5)	(6)	(16)
Amounts arising during the year	0	(1)	0
Reclassifications from AOCI	1	2	2
Net OCI during the year	1	1	10
Balance at end of year	(4)	(5)	(6)
Prior Service Costs [Member] | Reclassification out of Accumulated Other Comprehensive Income (Loss) due to Sale of U.K, Utility Business
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassifications from AOCI			8
Defined Benefit Plans Actuarial Gain (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of year	(124)	(152)	(3,046)
Amounts arising during the year	(41)	11	(1)
Reclassifications from AOCI	(3)	17	126
Net OCI during the year	(44)	28	2,894
Balance at end of year	$ (168)	$ (124)	(152)
Defined Benefit Plans Actuarial Gain (Loss) [Member] | Reclassification out of Accumulated Other Comprehensive Income (Loss) due to Sale of U.K, Utility Business
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassifications from AOCI			$ 2,769