Commitments and Contingent Liabilities (Litigation) (Details) $ in Millions	1 Months Ended	5 Months Ended	12 Months Ended				14 Months Ended
	Jul. 31, 2005 USD ($)	Mar. 31, 2017 cases	Dec. 31, 2017 cases	Dec. 31, 2016 USD ($) cases lawsuits	Dec. 31, 2015 USD ($)	Dec. 31, 2004	Dec. 31, 2017 cases	Jan. 31, 2012 USD ($)
PFOA Matters [Member]
Loss Contingencies [Line Items]
Accrual balance				$ 117.0
Indemnification assets				117.0
PFOA Matters [Member] | Environmental Issue [Member]
Loss Contingencies [Line Items]
Accrual balance				17.0
PFOA Matters: Drinking Water Actions [Member]
Loss Contingencies [Line Items]
Binding settlement agreement, class size						80,000
Loss Contingency, Estimate of Possible Loss				235.0
Escrow amount per settlement agreement								$ 1.0
Minimum escrow amount per settlement agreement								$ 0.5
Escrow amount disbursed (less than)				$ 1.0
PFOA MDL plaintiff cases voluntarily withdrawn				1
PFOA Matters: Multi-District Litigation [Member]
Loss Contingencies [Line Items]
Accrual balance				$ 100.0
Disease Categories for MDL				6
Lawsuits alleging personal injury - filed				3,550
Lawsuits alleging wrongful death				30
PFOA MDL plaintiffs				6
PFOA MDL plaintiff cases settled for immaterial amounts | cases				3
PFOA MDL plaintiff cases tried to a verdict that have been or will be appealed | cases				2
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: Multi-District Litigation [Member]
Loss Contingencies [Line Items]
Number of cases for trial in 2017 | cases			40
First cases tried prior to May 2017 | cases		2
Number of cases starting May 2017 | cases							38
Kidney cancer [Member] | PFOA Matters: Multi-District Litigation [Member]
Loss Contingencies [Line Items]
Lawsuits alleging personal injury - filed | lawsuits				210
PFOA MDL plaintiff cases settled for immaterial amounts | cases				2
Kidney cancer [Member] | PFOA Matters: Multi-District Litigation [Member] | Punitive [Member]
Loss Contingencies [Line Items]
Loss Contingency, Damages Awarded, Value					$ 0.0
Kidney cancer [Member] | PFOA Matters: Multi-District Litigation [Member] | Compensatory [Member]
Loss Contingencies [Line Items]
Loss Contingency, Damages Awarded, Value					$ 1.6
Testicular cancer [Member] | PFOA Matters: Multi-District Litigation [Member]
Loss Contingencies [Line Items]
Lawsuits alleging personal injury - filed | lawsuits				70
Ulcerative colitis [Member] | PFOA Matters: Multi-District Litigation [Member]
Loss Contingencies [Line Items]
Lawsuits alleging personal injury - filed | lawsuits				300
PFOA MDL plaintiff cases settled for immaterial amounts | cases				1
Preeclampsia [Member] | PFOA Matters: Multi-District Litigation [Member]
Loss Contingencies [Line Items]
Lawsuits alleging personal injury - filed | lawsuits				200
Thyroid disease [Member] | PFOA Matters: Multi-District Litigation [Member]
Loss Contingencies [Line Items]
Lawsuits alleging personal injury - filed | lawsuits				1,430
High cholesterol [Member] | PFOA Matters: Multi-District Litigation [Member]
Loss Contingencies [Line Items]
Lawsuits alleging personal injury - filed | lawsuits				1,340
Freeman [Member] | Testicular cancer [Member] | PFOA Matters: Multi-District Litigation [Member] | Punitive [Member]
Loss Contingencies [Line Items]
Loss Contingency, Damages Awarded, Value				$ 0.5
Freeman [Member] | Testicular cancer [Member] | PFOA Matters: Multi-District Litigation [Member] | Compensatory [Member]
Loss Contingencies [Line Items]
Loss Contingency, Damages Awarded, Value				5.1
Vigneron [Member] | Testicular cancer [Member] | PFOA Matters: Multi-District Litigation [Member] | Punitive [Member]
Loss Contingencies [Line Items]
Loss Contingency, Damages Awarded, Value				10.5
Vigneron [Member] | Testicular cancer [Member] | PFOA Matters: Multi-District Litigation [Member] | Compensatory [Member]
Loss Contingencies [Line Items]
Loss Contingency, Damages Awarded, Value				$ 2.0