Casualty, Environmental and Other Reserves - Narrative (Details)	12 Months Ended
	Dec. 31, 2023 USD ($) claim site	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Loss Contingencies [Line Items]
Reserves	$ 440,000,000	$ 436,000,000	$ 368,000,000	$ 314,000,000
Casualty Reserves
Loss Contingencies [Line Items]
Reserves	195,000,000	194,000,000	180,000,000	196,000,000
Self-insured retention amount per injury	$ 100,000,000
Individual claims expected to exceed self-insured retention amount | claim	0
Environmental
Loss Contingencies [Line Items]
Reserves	$ 154,000,000	161,000,000	108,000,000	76,000,000
Number of environmentally impaired sites | site	230
Other
Loss Contingencies [Line Items]
Reserves	$ 91,000,000	$ 81,000,000	$ 80,000,000	$ 42,000,000