v3.25.4
Employee Benefits - Fair Values for Pension Plans by Asset Category (Detail) - Pension - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Defined Benefit Plan Disclosure [Line Items]      
Defined benefit plan, plan assets amount $ 7,921 $ 6,802 $ 13,536
Fair Value, Inputs, Level 1, 2 and 3      
Defined Benefit Plan Disclosure [Line Items]      
Defined benefit plan, plan assets amount 5,717 4,146  
Fair Value, Inputs, Level 1, 2 and 3 | Cash and cash equivalents      
Defined Benefit Plan Disclosure [Line Items]      
Defined benefit plan, plan assets amount 882 542  
Fair Value, Inputs, Level 1, 2 and 3 | Equity securities      
Defined Benefit Plan Disclosure [Line Items]      
Defined benefit plan, plan assets amount 8 12  
Fair Value, Inputs, Level 1, 2 and 3 | U.S. Treasuries and agencies      
Defined Benefit Plan Disclosure [Line Items]      
Defined benefit plan, plan assets amount 938 720  
Fair Value, Inputs, Level 1, 2 and 3 | Corporate bonds      
Defined Benefit Plan Disclosure [Line Items]      
Defined benefit plan, plan assets amount 2,200 1,129  
Fair Value, Inputs, Level 1, 2 and 3 | International bonds      
Defined Benefit Plan Disclosure [Line Items]      
Defined benefit plan, plan assets amount 139 113  
Fair Value, Inputs, Level 1, 2 and 3 | Other      
Defined Benefit Plan Disclosure [Line Items]      
Defined benefit plan, plan assets amount 163 82  
Fair Value, Inputs, Level 1, 2 and 3 | Real estate      
Defined Benefit Plan Disclosure [Line Items]      
Defined benefit plan, plan assets amount 917 934  
Fair Value, Inputs, Level 1, 2 and 3 | Private equity      
Defined Benefit Plan Disclosure [Line Items]      
Defined benefit plan, plan assets amount 417 564  
Fair Value, Inputs, Level 1, 2 and 3 | Hedge funds      
Defined Benefit Plan Disclosure [Line Items]      
Defined benefit plan, plan assets amount 53 50  
Level 1      
Defined Benefit Plan Disclosure [Line Items]      
Defined benefit plan, plan assets amount 2,626 1,609  
Level 1 | Cash and cash equivalents      
Defined Benefit Plan Disclosure [Line Items]      
Defined benefit plan, plan assets amount 859 530  
Level 1 | Equity securities      
Defined Benefit Plan Disclosure [Line Items]      
Defined benefit plan, plan assets amount 8 12  
Level 1 | U.S. Treasuries and agencies      
Defined Benefit Plan Disclosure [Line Items]      
Defined benefit plan, plan assets amount 737 527  
Level 1 | Corporate bonds      
Defined Benefit Plan Disclosure [Line Items]      
Defined benefit plan, plan assets amount 1,069 627  
Level 1 | International bonds      
Defined Benefit Plan Disclosure [Line Items]      
Defined benefit plan, plan assets amount 0 0  
Level 1 | Other      
Defined Benefit Plan Disclosure [Line Items]      
Defined benefit plan, plan assets amount (47) (87)  
Level 1 | Real estate      
Defined Benefit Plan Disclosure [Line Items]      
Defined benefit plan, plan assets amount 0 0  
Level 1 | Private equity      
Defined Benefit Plan Disclosure [Line Items]      
Defined benefit plan, plan assets amount 0 0  
Level 1 | Hedge funds      
Defined Benefit Plan Disclosure [Line Items]      
Defined benefit plan, plan assets amount 0 0  
Level 2      
Defined Benefit Plan Disclosure [Line Items]      
Defined benefit plan, plan assets amount 1,729 1,016  
Level 2 | Cash and cash equivalents      
Defined Benefit Plan Disclosure [Line Items]      
Defined benefit plan, plan assets amount 23 12  
Level 2 | Equity securities      
Defined Benefit Plan Disclosure [Line Items]      
Defined benefit plan, plan assets amount 0 0  
Level 2 | U.S. Treasuries and agencies      
Defined Benefit Plan Disclosure [Line Items]      
Defined benefit plan, plan assets amount 201 193  
Level 2 | Corporate bonds      
Defined Benefit Plan Disclosure [Line Items]      
Defined benefit plan, plan assets amount 1,131 502  
Level 2 | International bonds      
Defined Benefit Plan Disclosure [Line Items]      
Defined benefit plan, plan assets amount 139 113  
Level 2 | Other      
Defined Benefit Plan Disclosure [Line Items]      
Defined benefit plan, plan assets amount 210 169  
Level 2 | Real estate      
Defined Benefit Plan Disclosure [Line Items]      
Defined benefit plan, plan assets amount 0 0  
Level 2 | Private equity      
Defined Benefit Plan Disclosure [Line Items]      
Defined benefit plan, plan assets amount 0 0  
Level 2 | Hedge funds      
Defined Benefit Plan Disclosure [Line Items]      
Defined benefit plan, plan assets amount 25 27  
Level 3      
Defined Benefit Plan Disclosure [Line Items]      
Defined benefit plan, plan assets amount 1,362 1,521 1,534
Level 3 | Cash and cash equivalents      
Defined Benefit Plan Disclosure [Line Items]      
Defined benefit plan, plan assets amount 0 0  
Level 3 | Equity securities      
Defined Benefit Plan Disclosure [Line Items]      
Defined benefit plan, plan assets amount 0 0  
Level 3 | U.S. Treasuries and agencies      
Defined Benefit Plan Disclosure [Line Items]      
Defined benefit plan, plan assets amount 0 0  
Level 3 | Corporate bonds      
Defined Benefit Plan Disclosure [Line Items]      
Defined benefit plan, plan assets amount 0 0  
Level 3 | International bonds      
Defined Benefit Plan Disclosure [Line Items]      
Defined benefit plan, plan assets amount 0 0  
Level 3 | Other      
Defined Benefit Plan Disclosure [Line Items]      
Defined benefit plan, plan assets amount 0 0  
Level 3 | Real estate      
Defined Benefit Plan Disclosure [Line Items]      
Defined benefit plan, plan assets amount 917 934 996
Level 3 | Private equity      
Defined Benefit Plan Disclosure [Line Items]      
Defined benefit plan, plan assets amount 417 564 512
Level 3 | Hedge funds      
Defined Benefit Plan Disclosure [Line Items]      
Defined benefit plan, plan assets amount 28 23 $ 26
Investments measured at NAV      
Defined Benefit Plan Disclosure [Line Items]      
Defined benefit plan, plan assets amount $ 2,204 $ 2,656