Commitments and Contingent Liabilities - Litigation (Narrative) (Details)			3 Months Ended	12 Months Ended
	Nov. 21, 2018 USD ($)	May 23, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2018 USD ($) lawsuit water_district	Dec. 31, 2004 resident	Dec. 31, 2017 USD ($) lawsuit
Loss Contingencies [Line Items]
Accrued environmental liability				$ 226,000,000		$ 253,000,000
Accrued litigation				53,000,000		48,000,000
Maximum [Member]
Loss Contingencies [Line Items]
Loss contingency, potential additional loss						$ 450,000,000
Funding for medical monitoring program [Member]
Loss Contingencies [Line Items]
Escrow deposit disbursements				$ 1,500,000
MDL Settlement [Member]
Loss Contingencies [Line Items]
Date of Agreement				Mar. 31, 2017
Total settlement amount			$ 670,700,000
PFOA MDL Settlement [Member]
Loss Contingencies [Line Items]
Lawsuits alleging personal injury - Filed | lawsuit				40
Settlement payments		$ 335,000,000
Benzene Related Illness [Member]
Loss Contingencies [Line Items]
Lawsuits alleging illness | lawsuit				19		17
PFOA Matters [Member]
Loss Contingencies [Line Items]
Accrual balance				$ 22,000,000		$ 14,000,000
Civil penalty and investigative costs	$ 13,000,000
Accrued environmental liability				75,000,000
Accrued litigation				65,000,000
PFOA Matters [Member] | Maximum [Member]
Loss Contingencies [Line Items]
Settlement payments				$ 25,000,000
Period of payments				5 years
PFOA Matters: Drinking Water Actions [Member]
Loss Contingencies [Line Items]
Binding settlement agreement, class size | resident					80,000
Number of water districts Company must provide treatment | water_district				6
PFOA Matters: Drinking Water Actions [Member] | Funding for medical monitoring program [Member]
Loss Contingencies [Line Items]
Loss contingency, potential additional loss				$ 235,000,000
PFOA Matters: Additional Actions [Member]
Loss Contingencies [Line Items]
Lawsuits alleging personal injury - Filed | lawsuit				3,500
DuPont [Member]
Loss Contingencies [Line Items]
Lawsuits alleging illness | lawsuit				25
DuPont [Member] | Maximum [Member]
Loss Contingencies [Line Items]
Settlement payments				$ 25,000,000
DuPont [Member] | Business Seeking to Recover Losses [Member]
Loss Contingencies [Line Items]
Lawsuits alleging illness | lawsuit				2
Asbestos Issue [Member]
Loss Contingencies [Line Items]
Lawsuits alleging personal injury - Filed | lawsuit				1,300		1,600
Accrual balance				$ 37,000,000		$ 38,000,000