Divestitures and Other Transactions PChem Narrative (Details) $ in Millions	Mar. 31, 2019 USD ($)
Accounts and Notes Receivable, Net [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Indemnification Assets	$ 84
Other Assets [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Indemnification Assets	289
Accrued and Other Current Liabilities [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Indemnification Liabilities	84
Other noncurrent obligations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Indemnification Liabilities	$ 289