|**Net Income Per Common Share (Tables)**              | 3 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
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|**Earnings Per Share [Abstract]**                     |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|Calculations For Basic And Diluted Earnings Per Share | The table shows calculations for basic and diluted earnings per share:(In millions, except per share data)Three months ended March 31,20242023Numerator:Net income—basic and diluted$755$225Denominator:Basic weighted-average common shares outstanding156.8157.2Effect of share-based awards:Stock options0.70.8Nonvested shares0.40.5Diluted weighted-average shares157.9158.5Earnings per share:Basic$4.82$1.43Diluted$4.78$1.42Number of anti-dilutive share-based awards1.31.0
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|(In millions, except per share data)                  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
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|Numerator:                                            |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|Net income—basic and diluted                          |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|Denominator:                                          |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|Basic weighted-average common shares outstanding      |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|Effect of share-based awards:                         |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|Stock options                                         |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|Nonvested shares                                      |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|Diluted weighted-average shares                       |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|Earnings per share:                                   |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|Basic                                                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|Diluted                                               |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|Number of anti-dilutive share-based awards            |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
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X- ReferencesNo definition available.
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duration X- DefinitionTabular disclosure of an entity's basic and diluted earnings per share calculations, including a reconciliation of numerators and denominators of the basic and diluted per-share computations for income from continuing operations.
+ ReferencesReference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 260 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482662/260-10-50-1
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