Casualty, Environmental and Other Reserves - Schedule of Balance Sheet Presentation (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Contingencies [Line Items]
Current	$ 184	$ 149
Long-term	295	313
Total	479	462	$ 440	$ 436
Total Casualty
Contingencies [Line Items]
Current	66	58
Long-term	147	150
Total	213	208	195	194
Personal Injury
Contingencies [Line Items]
Current	60	51
Long-term	94	91
Total	154	142
Occupational
Contingencies [Line Items]
Current	6	7
Long-term	53	59
Total	59	66
Environmental
Contingencies [Line Items]
Current	49	37
Long-term	107	114
Total	156	151	154	161
Other
Contingencies [Line Items]
Current	69	54
Long-term	41	49
Total	$ 110	$ 103	$ 91	$ 81