Employee Benefit Plans (Marketable Securities) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Retirement Benefits [Abstract]
Marketable securities held in trusts	$ 745	$ 774

Amount of investment in marketable security, classified as current.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(2))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

Name:	us-gaap_MarketableSecuritiesCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant