Investment And Other Income (Components Of Investment And Other Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2023	Mar. 31, 2022
Investment And Other Income [Abstract]
Interest and dividend income	$ 21	$ 2
Pension benefit	4	25
OPEB costs	(3)	(3)
OPEB remeasurement	(20)	54
All other, net		(1)
Total investment and other income, net	$ 2	$ 77

Amount of income (expense) related to nonoperating activities, classified as other.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.9)
-URI https://asc.fasb.org/extlink&oid=126953954&loc=SL114868664-224227

Name:	us-gaap_OtherNonoperatingIncomeExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration