Commitments and Contingent Liabilities Litigation (Details)		3 Months Ended		12 Months Ended
	Dec. 31, 2017 USD ($) lawsuits	Dec. 31, 2017 USD ($) lawsuits	Mar. 31, 2017 USD ($)	Dec. 31, 2017 USD ($) lawsuits	Dec. 31, 2004 USD ($)	Jan. 01, 2012
PFOA Matters: Multi-District Litigation [Member]
Loss Contingencies [Line Items]
Loss Contingency, Limited Sharing of Potential Future Liabilities, Period	5 years
Period for sharing for PFOA liabilities	5 years
Loss Contingency, Limited Sharing of Potential Future Liabilities, Third-Party Annual Liability Threshold	$ 25,000,000	$ 25,000,000		$ 25,000,000
PFOA Matters: Drinking Water Actions [Member]
Loss Contingencies [Line Items]
Loss Contingency, Number Of Water Districts Receiving Water Treatment						6
PFOA Matters: Multi-District Litigation [Member]
Loss Contingencies [Line Items]
Disease Categories for MDL	6	6		6
Lawsuits alleging personal injury filed | lawsuits	3,550	3,550		3,550
Litigation Settlement, Amount Awarded to Other Party			$ 670,700,000
Successor [Member] | PFOA Matters: Multi-District Litigation [Member]
Loss Contingencies [Line Items]
Indemnification Assets	$ 15,000,000	$ 15,000,000		$ 15,000,000
Accrual balance	15,000,000	15,000,000		15,000,000
Successor [Member] | PFOA Matters: Drinking Water Actions [Member]
Loss Contingencies [Line Items]
Escrow Deposit	$ 1,000,000	$ 1,000,000		$ 1,000,000
Predecessor [Member] | PFOA Matters: Drinking Water Actions [Member]
Loss Contingencies [Line Items]
Binding Settlement Agreement Class Size					80,000
Litigation Settlement, Liability For Medical Monitoring Program, Threshold					$ 235,000,000
Predecessor [Member] | Payment for Plaintiffs Attorney Fees [Member] | PFOA Matters: Drinking Water Actions [Member]
Loss Contingencies [Line Items]
Plaintiffs' attorneys' fees and expenses					23,000,000
Predecessor [Member] | Payment to fund community health project [Member] | PFOA Matters: Drinking Water Actions [Member]
Loss Contingencies [Line Items]
Payments to fund community health project					$ 70,000,000
WEST VIRGINIA | PFOA Matters: Drinking Water Actions [Member]
Loss Contingencies [Line Items]
Loss Contingency, Pending Claims, Number	5	5		5
OHIO | PFOA Matters: Drinking Water Actions [Member]
Loss Contingencies [Line Items]
Loss Contingency, Pending Claims, Number	4	4		4
NEW YORK | PFOA Matters: Drinking Water Actions [Member]
Loss Contingencies [Line Items]
Loss Contingency, Number of Plaintiffs				5
Loss Contingency, Pending Claims, Number	3	3		3
NORTH CAROLINA | PFOA Matters: Drinking Water Actions [Member]
Loss Contingencies [Line Items]
Loss Contingency, Pending Claims, Number	3	3		3
Loss Contingency, Number of Additional Plaintiffs		2
Chemours [Member] | PFOA Matters: Multi-District Litigation [Member]
Loss Contingencies [Line Items]
Additional annual PFOA liabilities for the next five years paid by Chemours	$ 25,000,000	$ 25,000,000		$ 25,000,000