XML 83 R58.htm IDEA: XBRL DOCUMENT v3.24.0.1
Note 5 - Retirement Plans (Details Textual) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate   5.00% 5.21% 2.80%
Defined Benefit Plan, Accumulated Other Comprehensive Income (Loss), Gain (Loss), before Tax   $ 643 $ 493  
Defined Benefit Plan, Accumulated Benefit Obligation   $ 3,600 $ 3,500  
Defined Benefit Plan, Expected Return on Plan Assets, Changes In Fair Value, Period (Year)   5 years    
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-Term Rate of Return on Plan Assets   5.25% 6.25% 6.25%
Weighted-average Maturity of Pension Plan Debt Portfolio (Year)   22 years 21 years  
Pension Plan Master Trust, Future Commitments for Additional Contributions, Private Equity Partnerships   $ 80 $ 91  
Pension Plan Master Trust, Future Commitments for Additional Contributions, Real Estate Partnerships and Funds   5 5  
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)   0 9 $ 85
Defined Contribution Plan, Cost   27 24 21
Railroad Retirement System Contributions   711 586 550
Collective-Bargaining Arrangement, Other [Member]        
Multiple-Employer Plan Accounted for as Multiemployer Plan, Contribution by Participating Entity   $ 16 $ 20 $ 30
Forecast [Member]        
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-Term Rate of Return on Plan Assets 5.25%      
Pension Plan [Member]        
Actual Return (Loss) on Pension Plan Assets, Net of Fees   6.00% (18.00%) 15.00%
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position   $ 520 $ 638  
Other Postretirement Benefits Plan [Member]        
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate   4.97% 5.23%  
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position   $ (104) $ (134)  
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)   $ (7) $ (2) $ (3)
Four Zero One Thrift Plan Before 2018 [Member]        
Defined Contribution Plan, Employer Matching Contribution, Percent of Match   50.00%    
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay   6.00%    
Four Zero One Thrift Plan 2018 Beyond [Member]        
Defined Contribution Plan, Employer Matching Contribution, Percent of Match   100.00%    
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay   6.00%    
Defined Contribution Plan, Additional Annual Employer Contribution, Percent of Employees Gross Pay   3.00%