Commitments and Contingencies (Details) (USD $)	3 Months Ended		3 Months Ended		3 Months Ended				3 Months Ended						1 Months Ended	3 Months Ended		3 Months Ended
	Mar. 31, 2012 Respirator Mask/Asbestos Litigation Claim Claimant	Dec. 31, 2011 Respirator Mask/Asbestos Litigation Claimant	Mar. 31, 2012 Respirator Mask/Asbestos Litigation - State of West Virginia	Mar. 31, 2012 Respirator Mask/Asbestos litigation - Excluding Aearo Technologies	Mar. 31, 2012 Insurance Disclaimer Action Insurer	Mar. 31, 2012 Respirator Mask/Asbestos Litigation - Aearo Technologies	Mar. 31, 2012 Environmental Matters - Remediation Y	Dec. 31, 2011 Environmental Matters - Remediation	Mar. 31, 2012 Environmental Matters - Regulatory Activities PFC Y	Mar. 31, 2012 Environmental Matters - Regulatory Activities Alabama DisposalSite Y	Mar. 31, 2012 Environmental Matters - Regulatory Activities Minnesota DisposalSite	Mar. 31, 2012 Environmental Matters - Litigation Morgan County, Alabama Claimant	Mar. 31, 2012 Environmental Matters - Litigation Lake Elmo, Minnesota	Mar. 31, 2012 Environmental Matters - Litigation Metropolitan Council, Minnesota TreatmentPlant	Jun. 30, 2009 Environmental Matters - Litigation New Jersey DisposalSite Defendant	Mar. 31, 2012 Environmental Matters - Other Environmental Liabilities Y	Dec. 31, 2011 Environmental Matters - Other Environmental Liabilities	Mar. 31, 2012 Environmental Matters - Other Environmental Liabilities Minnesota DisposalSite
Loss contingencies
Accrued loss contingency reserve	$ 133,000,000	$ 130,000,000				$ 29,000,000	$ 30,000,000	$ 28,000,000								$ 70,000,000	$ 75,000,000
Insurance receivables	124,000,000	121,000,000			15,000,000		15,000,000	15,000,000
Number of individual claimants	2,200	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 and being appealed	1
Number of additional defendants			2
Liability for asbestos and environmental claims gross-excluding Aearo Inc.				104,000,000
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
Annual fee paid to Cabot to retain responsibility and liability for products manufactured before July 11, 1995						400,000
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
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 (in years)										20
Number of sites where remediation work will continue throughout 2012											2
Total number of named plaintiffs, second purported class action												3
Claim asserted for alleged contamination, low end													50,000	50,000
Number of wastewater treatment plants from which PFC-containing sludge and biosolids may be discharged, low end of range														1
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 clean-up 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
Number of commercial waste disposal facilities used															2
Number of years remediation payments expected to be paid for applicable sites, high end of range							20									5
Number of former disposal sites with PFC present in soil and groundwater in Washington County Minnesota																		2
Increase in insurance liabilities	17,000,000
Increase in insurance recovery receivable	3,000,000
Litigation settlement awarded					$ 28,000,000
The period over which the litigation settlement is to be paid					P2Y