Summary of Significant Accounting Policies - Turnaround Expenses (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Petroleum Segment
Planned Major Maintenance Activities [Line Items]
Turnaround costs capitalized	$ 58	$ 60	$ 81
Petroleum Segment \| Minimum
Planned Major Maintenance Activities [Line Items]
Frequency of planned major maintenance activities	4 years
Petroleum Segment \| Maximum
Planned Major Maintenance Activities [Line Items]
Frequency of planned major maintenance activities	5 years
Nitrogen Fertilizer Segment
Planned Major Maintenance Activities [Line Items]
Frequency of planned major maintenance activities	3 years
Turnaround expenses incurred	$ 1	$ 2	$ 33