Commitments and Contingent Liabilities Environmental (Details) $ in Millions	Dec. 31, 2017 USD ($)
Successor [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies	$ 433
Accrual for Environmental Loss Contingencies, Potential Exposure in Excess of Accrual	920
Predecessor [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies	457
Superfund Sites [Member] | Successor [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies	67
Superfund Sites [Member] | Predecessor [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies	50
Chemours [Member] | Successor [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies	242
Accrual for Environmental Loss Contingencies, Potential Exposure in Excess of Accrual	430
Indemnification Agreement [Member] | Chemours [Member] | Successor [Member]
Loss Contingencies [Line Items]
Indemnification Assets	242
Indemnification Agreement [Member] | Chemours [Member] | Superfund Sites [Member] | Successor [Member]
Loss Contingencies [Line Items]
Indemnification Assets	$ 47