Casualty, Environmental and Other Reserves - Schedule of Casualty, Environmental and Other Reserves (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Loss Contingencies [Line Items]
Current	$ 133	$ 144
Long-term	302	292
Total	435	436
Total Casualty
Loss Contingencies [Line Items]
Current	47	50
Long-term	147	144
Total	194	194
Personal Injury
Loss Contingencies [Line Items]
Current	40	40
Long-term	87	86
Total	127	126
Occupational
Loss Contingencies [Line Items]
Current	7	10
Long-term	60	58
Total	67	68
Environmental
Loss Contingencies [Line Items]
Current	40	53
Long-term	117	108
Total	157	161
Other
Loss Contingencies [Line Items]
Current	46	41
Long-term	38	40
Total	$ 84	$ 81