Pensions and Other Postretirement Benefits - Fair Value of Plan Assets (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 2,766	$ 2,551
Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,133	1,079
Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,633	1,472
Common stock
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,107	1,054
Common stock | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,107	1,054
Common stock | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Debt securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	675	637
Debt securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Debt securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	675	637
Domestic equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	380	346
Domestic equity securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Domestic equity securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	380	346
International equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	294	362
International equity securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
International equity securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	294	362
Commingled funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	280	123
Commingled funds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Commingled funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	280	123
Government and agencies securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4	4
Government and agencies securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Government and agencies securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4	4
Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	26	25
Cash and cash equivalents | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	26	25
Cash and cash equivalents | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 0	$ 0