Casualty, Environmental and Other Reserves - Schedule of Casualty, Environmental and Other Reserves (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Loss Contingencies [Line Items]
Current	$ 138	$ 144
Long-term	299	292
Total	437	436
Total Casualty
Loss Contingencies [Line Items]
Current	47	50
Long-term	145	144
Total	192	194
Personal Injury
Loss Contingencies [Line Items]
Current	40	40
Long-term	86	86
Total	126	126
Occupational
Loss Contingencies [Line Items]
Current	7	10
Long-term	59	58
Total	66	68
Environmental
Loss Contingencies [Line Items]
Current	44	53
Long-term	116	108
Total	160	161
Other
Loss Contingencies [Line Items]
Current	47	41
Long-term	38	40
Total	$ 85	$ 81