Nature of Operations and Significant Accounting Policies - Narrative (Details)	3 Months Ended				9 Months Ended		21 Months Ended
	Sep. 30, 2023 USD ($) state mi	Sep. 30, 2022 USD ($)	Jun. 30, 2022 USD ($)	Mar. 31, 2022 USD ($)	Sep. 30, 2023 USD ($) state mi	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)	Mar. 26, 2021 phase property
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Rail route network, distance | mi	20,000				20,000
Number of states rail network serves | state	26				26
Proceeds from sale of property, plant, and equipment					$ 35,000,000	$ 51,000,000
Gain (loss) on disposition of property plant equipment	$ 6,000,000	$ 27,000,000			$ 26,000,000	$ 183,000,000
Virginia Line Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of property rights for sale | property								3
Number of phases to complete property rights sale transaction | phase								3
Proceeds from sale of property, plant, and equipment		0	$ 125,000,000				$ 525,000,000
Gain (loss) on disposition of property plant equipment		$ 0	$ 122,000,000	$ 20,000,000			$ 493,000,000