Commitments and Contingencies (Details 2) (USD $)	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2012	Sep. 30, 2012 Claim Claimant	Dec. 31, 2011 Claimant
Respirator Mask/Asbestos Litigation
Loss contingencies
Number of individual claimants		2,115	2,260
Number of total claims settled and taken to trial		9
Number of total claims tried to verdict		8
Number of total claims settled and tried to verdict		7
Number of total claims dismissed		1
Increase in insurance liabilities	$ 16,000,000	$ 66,000,000
Increase in insurance recovery receivable	15,000,000	39,000,000
Respirator Mask/Asbestos Litigation - State of West Virginia
Loss contingencies
Number of additional defendants		2
Insurance Disclaimer Action
Loss contingencies
Number of insurers who filed a declaratory judgment action against the company		2
Number of the entity's insurers named in the action, low end of range		60
Litigation settlement awarded		81,000,000
Litigation settlement awarded that has been received as of the end of the period		69,000,000
The period over which the litigation settlement is to be paid		2 years
Respirator Mask/Asbestos Litigation - Aearo Technologies
Loss contingencies
Annual fee paid to Cabot to retain responsibility and liability for products manufactured before July 11, 1995		400,000
Environmental Matters - Remediation
Loss contingencies
Number of years remediation payments expected to be paid for applicable sites		20 years
Environmental Matters - Regulatory Activities
Loss contingencies
Number of PFCs the EPA has proposed to have public water suppliers monitor		6
Number of years after phase-out decision in May 2000 that the Company stopped manufacturing and using vast majority of perfluorooctanyl compounds		2 years
Environmental Matters - Regulatory Activities | Alabama
Loss contingencies
Number of landfills to be tested by the entity pursuant to a Memorandum of Understanding with the EPA		3
Wastewater treatment plant sludge containing PFCs surrounding Decatur facility pursuant to a permit		20 years
Environmental Matters - Regulatory Activities | Minnesota
Loss contingencies
Number of sites where remediation work will continue throughout 2012		2
Environmental Matters - Litigation | Morgan County, Alabama
Loss contingencies
Total number of named plaintiffs, second purported class action		3
Environmental Matters - Litigation | Minnesota
Loss contingencies
Number of days court stayed discovery		180 days
Environmental Matters - Litigation | Lake Elmo, Minnesota
Loss contingencies
Claim asserted for alleged contamination, low end		50,000
Environmental Matters - Litigation | New Jersey
Loss contingencies
Lower end of range of number of companies served with a complaint		250
Number of companies, in addition to Maxus Energy, Tierra Solutions and Occidental Chemical involved in an enforcement action		2
Total cost of cleanup proposed by the EPA, of which the Company believes its applicable share, if any, is likely to be a fraction of one percent		1,000,000,000
Total cost of cleanup proposed by EPA of which company believes its applicable share to be fraction of this maximum percentage (as a percent)		1.00%
Number of commercial drum conditioning facilities used		2
Environmental Matters - Litigation | Metropolitan Council, Minnesota
Loss contingencies
Claim asserted for alleged contamination, low end		50,000
Number of wastewater treatment plants from which PFC-containing sludge and biosolids may allegedly be discharged by Metropolitan Council, low end of range		1
Environmental Matters - Other Environmental Litigation
Loss contingencies
Increase in insurance recovery receivable	$ 15,000,000	$ 15,000,000
Number of years remediation payments expected to be paid for applicable sites		5 years
Number of former disposal sites with PFC present in soil and groundwater in Washington County, Minnesota		2