Commitments and Contingent Liabilities (Litigation) (Narrative) (Details) $ in Millions	1 Months Ended	3 Months Ended	6 Months Ended	12 Months Ended
	Jul. 31, 2005 USD ($)	Jun. 30, 2017 USD ($) yr	Jun. 30, 2017 USD ($) yr	Dec. 31, 2004 resident	Mar. 31, 2017 USD ($)	Jan. 31, 2012 USD ($)
Loss Contingencies [Line Items]
Loss contingency accrual, period decrease		$ 30.0
Indemnification asset period decrease		15.0
PFOA Matters: Drinking Water Actions [Member]
Loss Contingencies [Line Items]
Binding settlement agreement, class size | resident				80,000
Loss contingency, potential additional loss		235.0	$ 235.0
Escrow deposit						$ 1.0
Minimum escrow amount per settlement agreement						$ 0.5
Escrow amount disbursed (less than)		1.0	1.0
PFOA Matters [Member]
Loss Contingencies [Line Items]
Accrual balance		656.0	656.0
Indemnification assets		335.0	335.0
PFOA Matters: Multi-District Litigation [Member]
Loss Contingencies [Line Items]
MDL Settlement Amount					$ 670.7
Accrual balance		640.7	640.7		670.7
Indemnification assets		$ 320.0	$ 320.0		$ 335.0
Disease Categories for MDL		6	6
Lawsuits alleging personal injury - Filed		3,550	3,550
Lawsuits alleging wrongful death		30	30
Loss Contingency, Loss in Period			$ 335.0
Loss Contingency, Loss in Period, after tax			$ 214.0
Payment for Plaintiffs Attorney Fees [Member] | PFOA Matters: Drinking Water Actions [Member]
Loss Contingencies [Line Items]
Settlement payments	$ 23.0
Payment to fund community health project [Member] | PFOA Matters: Drinking Water Actions [Member]
Loss Contingencies [Line Items]
Settlement payments	$ 70.0
Scenario, Forecast [Member] | PFOA Matters [Member]
Loss Contingencies [Line Items]
Period for sharing for PFOA Liabilities | yr		5	5
Additional annual PFOA liabilities for the next five years paid by Chemours		$ 25.0	$ 25.0
Additional annual PFOA liabilities for the next five years paid by DuPont		25.0	25.0
PFOA Matters [Member]
Loss Contingencies [Line Items]
Accrual balance		$ 15.0	$ 15.0