v3.26.1
Document and Entity Information
Jul. 24, 2026
Cover [Abstract]  
Entity Registrant Name CABOT CORP
Amendment Flag false
Entity Central Index Key 0000016040
Document Type 8-K
Document Period End Date Jul. 24, 2026
Entity Incorporation State Country Code DE
Entity File Number 1-5667
Entity Tax Identification Number 04-2271897
Entity Address, Address Line One TWO SEAPORT LANE
Entity Address, Address Line Two SUITE 1400
Entity Address, City or Town BOSTON
Entity Address, State or Province MA
Entity Address, Postal Zip Code 02210-2019
City Area Code (617)
Local Phone Number 345-0100
Written Communications false
Soliciting Material false
Pre Commencement Tender Offer false
Pre Commencement Issuer Tender Offer false
Security 12b Title Common Stock, $1 par value per share
Trading Symbol CBT
Security Exchange Name NYSE
Entity Emerging Growth Company false