Commitments and Contingent Liabilities Environmental (Details) $ in Millions	Mar. 31, 2019 USD ($)
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies	$ 384
Accrual for Environmental Loss Contingencies, Potential Exposure in Excess of Accrual	790
Superfund Sites [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies	54
Chemours [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies	185
Accrual for Environmental Loss Contingencies, Potential Exposure in Excess of Accrual	355
Chemours [Member] | Indemnification Agreement [Member]
Loss Contingencies [Line Items]
Indemnification Assets	185
Chemours [Member] | Indemnification Agreement [Member] | Superfund Sites [Member]
Loss Contingencies [Line Items]
Indemnification Assets	$ 35