Significant Accounting Policies	3 Months Ended
Dec. 31, 2024
Accounting Policies [Abstract]
Significant Accounting Policies	B. Significant Accounting Policies Full detail on the Company’s significant accounting policies may be obtained by referring to Note A in the 2024 10-K. Argentinian Government Actions The Company’s wholly-owned Argentinian subsidiary operates in a highly inflationary economy and, as a result, the functional currency of the subsidiary is Cabot’s reporting currency, the U.S. dollar. During the three months ended December 31, 2024 and 2023, the Company recorded foreign exchange losses of $2 million and $40 million, respectively, related to the revaluation of non-functional currency denominated monetary asset and liability balances. Of the $40 million of foreign exchange losses in the first quarter of fiscal 2024, $33 million related to a single devaluation action in December 2023 by the Argentine government. The Company invests cash in money market funds and recorded investment income of less than $1 million and $12 million, respectively, for the three months ended December 31, 2024 and 2023. The foreign exchange losses and investment gains are recorded in Other income (expense) in the Consolidated Statement of Operations. Recent Accounting Pronouncements In November 2024, the FASB issued a new standard, Expense Disaggregation Disclosures. The new guidance requires quantitative and qualitative disclosure of certain cost and expense categories in the notes to the financial statements for interim and annual reporting periods. The new standard is effective for the Company's fiscal years and interim periods beginning October 1, 2027, with early adoption permitted. The Company is currently evaluating the timing of adoption and evaluating the impact of the potential adoption of this standard on the Company’s Consolidated Financial Statements. In March 2024, the Securities and Exchange Commission (“SEC”) issued its final rule, The Enhancement and Standardization of Climate-Related Disclosures for Investors that requires the Company to provide certain climate-related information. The rule provides a phased-in compliance period and is effective for fiscal years beginning after December 15, 2024, with early adoption permitted. In April 2024, the SEC voluntarily stayed its rule pending completion of judicial review by the U.S. Court of Appeals for the Eighth Circuit and, therefore, the timing of the effectiveness of these disclosure requirements is uncertain. The Company is currently monitoring the timing of adoption and evaluating the impact of the potential adoption of this standard on the Company’s Consolidated Financial Statements. In December 2023, the FASB issued a new standard, Improvements to Income Tax Disclosures. The new guidance requires additional disclosures primarily related to the income tax rate reconciliation and income taxes paid. The new standard is effective for the Company’s fiscal years and interim periods beginning October 1, 2025. The Company is currently evaluating the impact of the adoption of this standard on the Company’s Consolidated Financial Statements. In November 2023, the FASB issued a new standard, Improvement to Reportable Segment Disclosures. The new guidance requires enhanced disclosure of significant reportable segment expenses. The new standard is effective for the Company’s current fiscal year which began October 1, 2024, and for interim periods beginning October 1, 2025. The Company is currently evaluating the impact of the adoption of this standard on the Company’s Consolidated Financial Statements.

Full detail on the Company’s significant accounting policies may be obtained by referring to Note A in the 2024 10-K.

The Company’s wholly-owned Argentinian subsidiary operates in a highly inflationary economy and, as a result, the functional currency of the subsidiary is Cabot’s reporting currency, the U.S. dollar. During the three months ended December 31, 2024 and 2023, the Company recorded foreign exchange losses of $2 million and $40 million, respectively, related to the revaluation of non-functional currency denominated monetary asset and liability balances. Of the $40 million of foreign exchange losses in the first quarter of fiscal 2024, $33 million related to a single devaluation action in December 2023 by the Argentine government. The Company invests cash in money market funds and recorded investment income of less than $1 million and $12 million, respectively, for the three months ended December 31, 2024 and 2023. The foreign exchange losses and investment gains are recorded in Other income (expense) in the Consolidated Statement of Operations.

Recent Accounting Pronouncements

In November 2024, the FASB issued a new standard, Expense Disaggregation Disclosures. The new guidance requires quantitative and qualitative disclosure of certain cost and expense categories in the notes to the financial statements for interim and annual reporting periods. The new standard is effective for the Company's fiscal years and interim periods beginning October 1, 2027, with early adoption permitted. The Company is currently evaluating the timing of adoption and evaluating the impact of the potential adoption of this standard on the Company’s Consolidated Financial Statements.

In March 2024, the Securities and Exchange Commission (“SEC”) issued its final rule, The Enhancement and Standardization of Climate-Related Disclosures for Investors that requires the Company to provide certain climate-related information. The rule provides a phased-in compliance period and is effective for fiscal years beginning after December 15, 2024, with early adoption permitted. In April 2024, the SEC voluntarily stayed its rule pending completion of judicial review by the U.S. Court of Appeals for the Eighth Circuit and, therefore, the timing of the effectiveness of these disclosure requirements is uncertain. The Company is currently monitoring the timing of adoption and evaluating the impact of the potential adoption of this standard on the Company’s Consolidated Financial Statements.

In December 2023, the FASB issued a new standard, Improvements to Income Tax Disclosures. The new guidance requires additional disclosures primarily related to the income tax rate reconciliation and income taxes paid. The new standard is effective for the Company’s fiscal years and interim periods beginning October 1, 2025. The Company is currently evaluating the impact of the adoption of this standard on the Company’s Consolidated Financial Statements.

In November 2023, the FASB issued a new standard, Improvement to Reportable Segment Disclosures. The new guidance requires enhanced disclosure of significant reportable segment expenses. The new standard is effective for the Company’s current fiscal year which began October 1, 2024, and for interim periods beginning October 1, 2025. The Company is currently evaluating the impact of the adoption of this standard on the Company’s Consolidated Financial Statements.