Divestitures and Other Transactions Divestitures and Other Transactions - PChem Results of Operations (Details) - USD ($) $ in Millions	4 Months Ended	8 Months Ended	12 Months Ended
	Dec. 31, 2017	Aug. 31, 2017	Dec. 31, 2019	Dec. 31, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Indemnification Assets			$ 202
Income (loss) from discontinued operations after income taxes	$ 568	$ (1,403)	671	$ (1,748)
Performance Chemicals [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Other Operating Charges		335
Other Income - net		3
(Loss) Income from Discontinued Operation, before Income Tax		(332)
Provision for (Benefit from) Income Taxes, Discontinued Operation		(125)
Income (loss) from discontinued operations after income taxes		(207)
Loss Related To Litigation Settlement, Net Of Tax		$ 214
Performance Chemicals [Member] | Accounts and Notes Receivable [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Indemnification Assets			54
Performance Chemicals [Member] | Other Assets [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Indemnification Assets			302
Performance Chemicals [Member] | Accrued and Other Current Liabilities [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Indemnified Liabilities			54
Performance Chemicals [Member] | Other Noncurrent Obligations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Indemnified Liabilities			$ 302