XML 47 R38.htm IDEA: XBRL DOCUMENT
v3.22.1

Contingencies - Additional Information (Detail) - USD ($) $ in Millions | Mar. 31, 2022 | Sep. 30, 2021
--- | --- | ---
Respirator Liabilities [Member] |  |
Loss Contingencies [Line Items] |  |
Respirator reserve | $ 42 | $ 44

X
- Definition The estimated aggregate amount of losses related to respirator liability claims as of the balance sheet date. + References No definition available. + Details
Name: | cbt_RespiratorReserve
Namespace Prefix: | cbt_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_LossContingenciesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_LossContingenciesByNatureOfContingencyAxis=cbt_RespiratorLiabilitiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |