v3.25.4
Pensions and Other Postretirement Benefits - Assets and Fair Value Measurements (Details) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
U.S.    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets $ 38,552 $ 38,298
U.S. | Common and preferred stocks    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets 14 15
U.S. | Government and agency debt securities    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets 12,025 11,728
U.S. | Corporate and other debt securities    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets 13,820 15,155
U.S. | Other investments, net    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets (2,833) (3,348)
U.S. | Investment funds    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets $ 9,841 $ 10,025
Defined Benefit Plan, Plan Assets, Fair Value by Hierarchy and NAV [Extensible Enumeration] Fair Value Measured at Net Asset Value Per Share Fair Value Measured at Net Asset Value Per Share
U.S. | Private equity and debt investments    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets $ 3,216 $ 2,961
Defined Benefit Plan, Plan Assets, Fair Value by Hierarchy and NAV [Extensible Enumeration] Fair Value Measured at Net Asset Value Per Share Fair Value Measured at Net Asset Value Per Share
U.S. | Real estate investments    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets $ 2,645 $ 2,655
Defined Benefit Plan, Plan Assets, Fair Value by Hierarchy and NAV [Extensible Enumeration] Fair Value Measured at Net Asset Value Per Share Fair Value Measured at Net Asset Value Per Share
U.S. | Other plan assets (liabilities), net    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets $ (176) $ (893)
U.S. | Fair Value, Inputs, Level 1, Level 2, and Level 3    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets 23,026 23,550
U.S. | Level 1    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets (2) (60)
U.S. | Level 1 | Common and preferred stocks    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets 14 15
U.S. | Level 1 | Government and agency debt securities    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets 0 0
U.S. | Level 1 | Corporate and other debt securities    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets 0 0
U.S. | Level 1 | Other investments, net    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets (16) (75)
U.S. | Level 2    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets 22,640 23,221
U.S. | Level 2 | Common and preferred stocks    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets 0 0
U.S. | Level 2 | Government and agency debt securities    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets 12,025 11,728
U.S. | Level 2 | Corporate and other debt securities    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets 13,820 15,155
U.S. | Level 2 | Other investments, net    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets (3,205) (3,662)
U.S. | Level 2 | Canadian repurchase agreements    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets 4,100 3,600
U.S. | Level 3    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets 388 389
U.S. | Level 3 | Common and preferred stocks    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets 0 0
U.S. | Level 3 | Government and agency debt securities    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets 0 0
U.S. | Level 3 | Corporate and other debt securities    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets 0 0
U.S. | Level 3 | Other investments, net    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets 388 389
U.S. | Fair Value Measured at Net Asset Value Per Share    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets 15,702 15,641
Non-U.S.    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets 9,113 9,121
Non-U.S. | Common and preferred stocks    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets 0 98
Non-U.S. | Government and agency debt securities    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets 2,408 2,267
Non-U.S. | Corporate and other debt securities    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets 2,154 2,344
Non-U.S. | Other investments, net    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets (61) (108)
Non-U.S. | Investment funds    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets $ 3,312 $ 3,303
Defined Benefit Plan, Plan Assets, Fair Value by Hierarchy and NAV [Extensible Enumeration] Fair Value Measured at Net Asset Value Per Share Fair Value Measured at Net Asset Value Per Share
Non-U.S. | Private equity and debt investments    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets $ 422 $ 406
Defined Benefit Plan, Plan Assets, Fair Value by Hierarchy and NAV [Extensible Enumeration] Fair Value Measured at Net Asset Value Per Share Fair Value Measured at Net Asset Value Per Share
Non-U.S. | Real estate investments    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets $ 700 $ 689
Defined Benefit Plan, Plan Assets, Fair Value by Hierarchy and NAV [Extensible Enumeration] Fair Value Measured at Net Asset Value Per Share Fair Value Measured at Net Asset Value Per Share
Non-U.S. | Other plan assets (liabilities), net    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets $ 178 $ 122
Non-U.S. | Fair Value, Inputs, Level 1, Level 2, and Level 3    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets 4,501 4,601
Non-U.S. | Level 1    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets 2 106
Non-U.S. | Level 1 | Common and preferred stocks    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets 0 98
Non-U.S. | Level 1 | Government and agency debt securities    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets 0 0
Non-U.S. | Level 1 | Corporate and other debt securities    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets 0 0
Non-U.S. | Level 1 | Other investments, net    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets 2 8
Non-U.S. | Level 2    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets 4,452 4,447
Non-U.S. | Level 2 | Common and preferred stocks    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets 0 0
Non-U.S. | Level 2 | Government and agency debt securities    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets 2,402 2,262
Non-U.S. | Level 2 | Corporate and other debt securities    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets 2,149 2,336
Non-U.S. | Level 2 | Other investments, net    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets (99) (151)
Non-U.S. | Level 2 | Canadian repurchase agreements    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets 125 185
Non-U.S. | Level 3    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets 47 48
Non-U.S. | Level 3 | Common and preferred stocks    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets 0 0
Non-U.S. | Level 3 | Government and agency debt securities    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets 6 5
Non-U.S. | Level 3 | Corporate and other debt securities    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets 5 8
Non-U.S. | Level 3 | Other investments, net    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets 36 35
Non-U.S. | Fair Value Measured at Net Asset Value Per Share    
Defined Benefit Plan Disclosure [Line Items]    
Net plan assets $ 4,434 $ 4,398