Fair Value (Gains (Losses) Related to the Trust) (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2022	Mar. 31, 2021
Rabbi Trust
Schedule of Investments [Line Items]
Gains (losses) related to the trust	$ (1)	$ 2
Equity securities
Schedule of Investments [Line Items]
Gains (losses) related to the trust	(1)	2
Fixed income securities
Schedule of Investments [Line Items]
Gains (losses) related to the trust	$ 0	$ 0

Amount of realized and unrealized gain (loss) on investment.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227

Reference 3: http://www.xbrl.org/2003/role/recommendedDisclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
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