Discontinued Operations and Disposal Groups (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sales of property and businesses, net of cash divested			$ 295	$ 47
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal	$ 220	$ 0	220	(44)
Packaging & Specialty Plastics [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal	35	0	35	0
Corporate Segment [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal	185	$ 0	185	$ (44)
Rail Infrastructure Operations and Assets [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sales of property and businesses, net of cash divested	303
Disposal Group, Including Discontinued Operation, Assets, Noncurrent	68		68
Disposal Group, Including Discontinued Operation, Goodwill	2		2
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal	233
Rail Infrastructure Operations and Assets [Member] | Packaging & Specialty Plastics [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Assets	16		16
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal	48
Rail Infrastructure Operations and Assets [Member] | Corporate Segment [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Assets	54		54
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal	185
Marine and Terminal Operations and Assets [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Expected Cash Proceeds from sale of assets and related operations	$ 620		$ 620