Cabot (CBT) 10-Q 6 Aug 24 2024 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Jun. 30, 2024	Aug. 01, 2024
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2024
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q3
Trading Symbol	CBT
Entity Registrant Name	Cabot Corporation
Entity Central Index Key	0000016040
Entity Current Reporting Status	Yes
Current Fiscal Year End Date	--09-30
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		54,823,821
Entity Shell Company	false
Entity Small Business	false
Entity Emerging Growth Company	false
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
Security Exchange Name	NYSE
Title of 12(b) Security	Common Stock, $1 par value per share
Entity Incorporation, State or Country Code	DE
Document Quarterly Report	true
Document Transition Report	false
Entity Interactive Data Current	Yes

Consolidated Statements of Oper

Consolidated Statements of Operations (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Income Statement [Abstract]
Net sales and other operating revenues	$ 1,016	$ 968	$ 2,993	$ 2,966
Cost of sales	760	745	2,273	2,352
Gross profit	256	223	720	614
Selling and administrative expenses	68	58	210	184
Research and technical expenses	16	15	46	43
Loss on sale of business				3
Income (loss) from operations	172	150	464	384
Interest and dividend income	8	7	25	22
Interest expense	(19)	(24)	(62)	(69)
Other income (expense)	(3)	(3)	(33)	(13)
Income (loss) from operations before income taxes and equity in earnings of affiliated companies	158	130	394	324
(Provision) benefit for income taxes	(40)	(41)	(121)	(90)
Equity in earnings of affiliated companies, net of tax	2	1	5	4
Net income (loss)	120	90	278	238
Net income (loss) attributable to noncontrolling interests, net of tax	11	8	35	27
Net income (loss) attributable to Cabot Corporation	$ 109	$ 82	$ 243	$ 211
Weighted-average common shares outstanding:
Basic	55.1	56.1	55.3	56.2
Diluted	55.7	56.5	55.8	56.7
Earnings (loss) per common share:
Basic	$ 1.96	$ 1.44	$ 4.34	$ 3.68
Diluted	$ 1.94	$ 1.43	$ 4.3	$ 3.65

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 120	$ 90	$ 278	$ 238
Other comprehensive income (loss), net of tax
Foreign currency translation adjustment, net of tax	(66)	(20)	(19)	117
Derivatives: net investment hedges
(Gains) losses reclassified to interest expense, net of tax	(1)	(1)	(3)	(4)
(Gains) losses excluded from effectiveness testing and amortized to interest expense, net of tax	1		2	1
Pension and other post-retirement benefit liability adjustments, net of tax			(1)	(1)
Other comprehensive income (loss), net of tax (provision) benefit of $ (1), $ -, $ 11 and $ -	(66)	(21)	(21)	113
Comprehensive income (loss)	54	69	257	351
Net income (loss) attributable to noncontrolling interests, net of tax	11	8	35	27
Foreign currency translation adjustment attributable to noncontrolling interests, net of tax	(1)	(6)	(1)	3
Comprehensive income (loss) attributable to noncontrolling interests	10	2	34	30
Comprehensive income (loss) attributable to Cabot Corporation	$ 44	$ 67	$ 223	$ 321

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Loss) (Unaudited) (Parenthetical) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Jun. 30, 2024	Jun. 30, 2024
Statement of Comprehensive Income [Abstract]
Net of tax (provision) benefit	$ (1)	$ 11

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($) $ in Millions	Jun. 30, 2024	Sep. 30, 2023
Current assets:
Cash and cash equivalents	$ 197	$ 238
Accounts and notes receivable, net of reserve for doubtful accounts of $5 and $2	732	695
Inventories:
Raw materials	145	148
Finished goods	341	374
Other	67	63
Total inventories	553	585
Prepaid expenses and other current assets	109	108
Total current assets	1,591	1,626
Property, plant and equipment	3,907	3,827
Accumulated depreciation	(2,477)	(2,415)
Net property, plant and equipment	1,430	1,412
Goodwill	132	134
Equity affiliates	24	20
Intangible assets, net	55	60
Deferred income taxes	166	180
Other assets	182	172
Total assets	3,580	3,604
Current liabilities:
Short-term borrowings	49	174
Accounts payable and accrued liabilities	626	600
Income taxes payable	34	40
Current portion of long-term debt	8	8
Total current liabilities	717	822
Long-term debt	1,083	1,094
Deferred income taxes	40	50
Other liabilities	244	231
Contingencies (Note E)
Preferred stock:
Authorized: 2,000,000 shares of $1 par value, Issued and Outstanding: None and none
Common stock:
Authorized: 200,000,000 shares of $1 par value, Issued: 54,949,872 and 55,379,636 shares, Outstanding: 54,816,803 and 55,243,804 shares	55	55
Less cost of 133,069 and 135,832 shares of common treasury stock	(3)	(3)
Retained earnings	1,676	1,574
Accumulated other comprehensive income (loss)	(382)	(362)
Total Cabot Corporation stockholders' equity	1,346	1,264
Noncontrolling interests	150	143
Total stockholders' equity	1,496	1,407
Total liabilities and stockholders' equity	$ 3,580	$ 3,604

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) (Unaudited) - USD ($) $ in Millions	Jun. 30, 2024	Sep. 30, 2023
Statement of Financial Position [Abstract]
Accounts and notes receivable, reserve for doubtful accounts	$ 5	$ 2
Preferred stock, authorized shares	2,000,000	2,000,000
Preferred stock, par value	$ 1	$ 1
Preferred stock, Issued shares	0	0
Preferred stock, Outstanding shares	0	0
Common stock, authorized shares	200,000,000	200,000,000
Common stock, par value	$ 1	$ 1
Common stock, issued shares	54,949,872	55,379,636
Common stock, outstanding shares	54,816,803	55,243,804
Common treasury stock, shares	133,069	135,832

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	9 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Cash Flows from Operating Activities:
Net income (loss)	$ 278	$ 238
Adjustments to reconcile net income (loss) to cash provided by operating activities:
Depreciation and amortization	114	107
Loss on sale of business		3
Gain on sale of land		(1)
Deferred tax provision (benefit)	7	(1)
Equity in earnings of affiliated companies	(5)	(4)
Share-based compensation	19	15
Other non-cash (income) expense	60	2
Cash dividends received from equity affiliates	1	2
Changes in assets and liabilities:
Accounts and notes receivable	(47)	173
Inventories	27	100
Prepaid expenses and other assets	(14)	17
Accounts payable and accrued liabilities	38	(177)
Income taxes payable	(6)	(18)
Other liabilities	16	1
Cash provided by (used in) operating activities	488	457
Cash Flows from Investing Activities:
Additions to property, plant and equipment	(149)	(166)
Proceeds from sale of land		7
Proceeds from sale of business		6
Proceeds from insurance settlements		12
Other	3	2
Cash provided by (used in) investing activities	(146)	(139)
Cash Flows from Financing Activities:
Proceeds from short-term borrowings		24
Repayments of short-term borrowings	(1)	(48)
Proceeds from issuance (repayments) of commercial paper, net	(123)	(188)
Proceeds from long-term debt, net of issuance costs	14	79
Repayments of long-term debt	(29)	(88)
Purchases of common stock	(106)	(48)
Proceeds from sales of common stock	15	4
Cash dividends paid to noncontrolling interests	(27)	(41)
Cash dividends paid to common stockholders	(69)	(65)
Cash provided by (used in) financing activities	(326)	(371)
Effects of exchange rate changes on cash	(57)	67
Increase (decrease) in cash and cash equivalents	(41)	14
Cash and cash equivalents at beginning of period	238	206
Cash and cash equivalents at end of period	$ 197	$ 220

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Millions	Total	Common Stock, Net of Treasury Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total Cabot Corporation Stockholders' Equity [Member]	Noncontrolling Interests [Member]
Beginning Balance at Sep. 30, 2022	$ 1,032	$ 52	$ 1	$ 1,284	$ (439)	$ 898	$ 134
Beginning Balance, Shares at Sep. 30, 2022		56,249
Net income (loss)	66			54		54	12
Total other comprehensive income (loss)	87				81	81	6
Cash dividends paid, Common stock, per share	(21)			(21)		(21)
Cash dividends declared to noncontrolling interests	(2)						(2)
Issuance of stock under equity compensation plans	3	$ 1	2			3
Issuance of stock under equity compensation plans, Shares		309
Share-based compensation	11		11			11
Purchase and retirement of common stock	(17)		(14)	(3)		(17)
Purchase and retirement of common stock, Shares		(242)
Ending Balance at Dec. 31, 2022	1,159	$ 53		1,314	(358)	1,009	150
Ending Balance, Shares at Dec. 31, 2022		56,316
Beginning Balance at Sep. 30, 2022	1,032	$ 52	1	1,284	(439)	898	134
Beginning Balance, Shares at Sep. 30, 2022		56,249
Net income (loss)	238
Total other comprehensive income (loss)	113
Ending Balance at Jun. 30, 2023	1,266	$ 53		1,407	(329)	1,131	135
Ending Balance, Shares at Jun. 30, 2023		55,937
Beginning Balance at Dec. 31, 2022	1,159	$ 53		1,314	(358)	1,009	150
Beginning Balance, Shares at Dec. 31, 2022		56,316
Net income (loss)	82			75		75	7
Total other comprehensive income (loss)	47				44	44	3
Cash dividends paid, Common stock, per share	(21)			(21)		(21)
Cash dividends declared to noncontrolling interests	(27)						(27)
Issuance of stock under equity compensation plans	1		1			1
Issuance of stock under equity compensation plans, Shares		29
Share-based compensation	7		7			7
Purchase and retirement of common stock	(16)		(8)	(8)		(16)
Purchase and retirement of common stock, Shares		(199)
Ending Balance at Mar. 31, 2023	1,232	$ 53		1,360	(314)	1,099	133
Ending Balance, Shares at Mar. 31, 2023		56,146
Net income (loss)	90			82		82	8
Total other comprehensive income (loss)	(21)				(15)	(15)	(6)
Cash dividends paid, Common stock, per share	(23)			(23)		(23)
Issuance of stock under equity compensation plans, Shares		4
Share-based compensation	3		3			3
Purchase and retirement of common stock	(15)		(3)	(12)		(15)
Purchase and retirement of common stock, Shares		(213)
Ending Balance at Jun. 30, 2023	1,266	$ 53		1,407	(329)	1,131	135
Ending Balance, Shares at Jun. 30, 2023		55,937
Beginning Balance at Sep. 30, 2023	1,407	$ 52		1,574	(362)	1,264	143
Beginning Balance, Shares at Sep. 30, 2023		55,244
Net income (loss)	61			50		50	11
Total other comprehensive income (loss)	61				57	57	4
Cash dividends paid, Common stock, per share	(22)			(22)		(22)
Cash dividends declared to noncontrolling interests	(12)						(12)
Issuance of stock under equity compensation plans	7		7			7
Issuance of stock under equity compensation plans, Shares		441
Share-based compensation	6		6			6
Purchase and retirement of common stock	(33)		(13)	(20)		(33)
Purchase and retirement of common stock, Shares		(260)
Ending Balance at Dec. 31, 2023	1,475	$ 52		1,582	(305)	1,329	146
Ending Balance, Shares at Dec. 31, 2023		55,425
Beginning Balance at Sep. 30, 2023	1,407	$ 52		1,574	(362)	1,264	143
Beginning Balance, Shares at Sep. 30, 2023		55,244
Net income (loss)	278
Total other comprehensive income (loss)	(21)
Ending Balance at Jun. 30, 2024	1,496	$ 52		1,676	(382)	1,346	150
Ending Balance, Shares at Jun. 30, 2024		54,817
Beginning Balance at Dec. 31, 2023	1,475	$ 52		1,582	(305)	1,329	146
Beginning Balance, Shares at Dec. 31, 2023		55,425
Net income (loss)	97			84		84	13
Total other comprehensive income (loss)	(16)				(12)	(12)	(4)
Cash dividends paid, Common stock, per share	(23)			(23)		(23)
Cash dividends declared to noncontrolling interests	(15)						(15)
Issuance of stock under equity compensation plans	6		6			6
Issuance of stock under equity compensation plans, Shares		122
Share-based compensation	7		7			7
Purchase and retirement of common stock	(24)		(13)	(11)		(24)
Purchase and retirement of common stock, Shares		(289)
Ending Balance at Mar. 31, 2024	1,507	$ 52		1,632	(317)	1,367	140
Ending Balance, Shares at Mar. 31, 2024		55,258
Net income (loss)	120			109		109	11
Total other comprehensive income (loss)	(66)				(65)	(65)	(1)
Cash dividends paid, Common stock, per share	(24)			(24)		(24)
Issuance of stock under equity compensation plans	2	$ 1	1			2
Issuance of stock under equity compensation plans, Shares		57
Share-based compensation	6		6			6
Purchase and retirement of common stock	(49)	$ (1)	$ (7)	(41)		(49)
Purchase and retirement of common stock, Shares		(498)
Ending Balance at Jun. 30, 2024	$ 1,496	$ 52		$ 1,676	$ (382)	$ 1,346	$ 150
Ending Balance, Shares at Jun. 30, 2024		54,817

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Stockholders' Equity (Unaudited) (Parenthetical) - $ / shares	3 Months Ended
	Jun. 30, 2024	Mar. 31, 2024	Dec. 31, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022
Statement of Stockholders' Equity [Abstract]
Common stock, cash dividends paid, per share	$ 0.43	$ 0.4	$ 0.4	$ 0.4	$ 0.37	$ 0.37

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Pay vs Performance Disclosure
Net Income (Loss)	$ 109	$ 82	$ 243	$ 211

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Jun. 30, 2024
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false
Rule 10b5-1 Arrangement Modified	false
Non-Rule 10b5-1 Arrangement Modified	false

Basis of Presentation

Basis of Presentation	9 Months Ended
	Jun. 30, 2024
Accounting Policies [Abstract]
Basis of Presentation	A. Basis of Presentation The consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States (“U.S.”) (“GAAP”) and include the accounts of Cabot Corporation (“Cabot” or the “Company”) and its wholly-owned subsidiaries and majority-owned and controlled U.S. and non-U.S. subsidiaries. Additionally, Cabot considers consolidation of entities over which control is achieved through means other than voting rights. Intercompany transactions have been eliminated in consolidation. The unaudited consolidated financial statements have been prepared in accordance with the requirements of Form 10-Q and consequently do not include all disclosures required by Form 10-K. Additional information may be obtained by referring to Cabot’s Annual Report on Form 10-K for its fiscal year ended September 30, 2023 (the “2023 10-K”). The financial information submitted herewith is unaudited and reflects all adjustments which are, in the opinion of management, necessary to provide a fair statement of the results for the interim periods ended June 30, 2024 and 2023. All such adjustments are of a normal rec urring nature. The results for interim periods are not necessarily indicative of the results to be expected for the fiscal year.

Significant Accounting Policies

Significant Accounting Policies	9 Months Ended
	Jun. 30, 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 2023 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 and nine months ended June 30, 2024 , the Company recorded foreign exchange losses of $ 2 million and $ 42 million, respectively, related to the revaluation of non-functional currency denominated monetary asset and liability balances, of which $ 33 million related to a single devaluation action in December 2023 by the newly-elected Argentine government. The Company invests cash in money market funds and recorded investment income of nil and $ 16 million, respectively, for the three and nine months ended June 30, 2024. The foreign exchange losses and investment gains are recorded in Other income (expense) in the Consolidated Statement of Operations. During the second quarter of fiscal 2024, the Company purchased $ 30 million in BOPREAL bonds (standing for “Bond for the Reconstruction of a Free Argentina” in Spanish), which are U.S. dollar-denominated securities issued by the Central Bank of Argentina, as part of an Argentine government program to settle foreign payables for importers with debts for goods with customs registration and/or services, incurred on or prior to December 12, 2023. The Company subsequently sold the bonds for $ 22 million and utilized the proceeds to partially repay its foreign payables in Argentina. The purchase and proceeds of BOPREAL bonds are included in the Changes in Prepaid expenses and other assets in the Consolidated Statement of Cash Flows. The $ 8 million investment loss is included in Other non-cash (income) expense in the Consolidated Statement of Cash Flows and in Other income (expense) in the Consolidated Statement of Operations. In accordance with Argentine government regulations, the Company purchased an additional $ 8 million of U.S. dollars in the third quarter of fiscal 2024 at a foreign exchange loss of $ 2 million and utilized the funds to complete the settlement of outstanding foreign payables incurred on or prior to December 12, 2023. Recently Adopted Accounting Standards In November 2022, the Financial Accounting Standards Board (“FASB”) issued a new standard on the disclosure of supplier financing programs. The new standard requires qualitative and quantitative disclosures as to the nature and potential magnitude of such programs in addition to program activity and changes for the periods presented. The Company adopted this standard on October 1, 2023. See Note J for disclosures related to the Company's supplier financing programs. The adoption of this standard did not have a material impact on the Company's Consolidated Financial Statements. Recent Accounting Pronouncements 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 November 2023, the FASB issued a new standard, Improvement to Reportable Segment Disclosures. The new guidance enhances the disclosure of significant reportable segment expenses. The new standard is effective for the Company’s fiscal years beginning 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. 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.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	9 Months Ended
	Jun. 30, 2024
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	C. Goodwill and Intangible Assets The carrying amount of goodwill attributable to each reportable segment and the changes in those balances during the nine months ended June 30, 2024 are as follows: Reinforcement Performance Total (In millions) Balance at September 30, 2023 $ 51 $ 83 $ 134 Foreign currency impact ( 2 ) — ( 2 ) Balance at June 30, 2024 $ 49 $ 83 $ 132 The following table provides information regarding the Company’s intangible assets: June 30, 2024 September 30, 2023 Gross Accumulated Net Gross Accumulated Net (In millions) Intangible assets with finite lives Developed technologies $ 33 $ ( 11 ) $ 22 $ 34 $ ( 10 ) $ 24 Trademarks 2 ( 1 ) 1 2 ( 1 ) 1 Customer relationships 63 ( 31 ) 32 65 ( 30 ) 35 Total intangible assets $ 98 $ ( 43 ) $ 55 $ 101 $ ( 41 ) $ 60 Intangible assets are amortized over their estimated useful lives, which range betwee n ten and twenty-five years , with a weighted average amortization period of approximately seventeen years . Amortiza tion expense was $ 1 million for both the three months ended June 30, 2024 and 2023 . Amortization expense was $ 4 million for both the nine months ended June 30, 2024 and 2023. Amortization expense is included in Cost of sales, Selling and administrative expenses and Research and technical expenses in the Consolidated Statements of Operations. Total amortization expense is estimated to be approximately $ 6 million each year for the next five fiscal years.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss) ("AOCI")	9 Months Ended
	Jun. 30, 2024
Stockholders' Equity Note [Abstract]
Accumulated Other Comprehensive Income (Loss) ("AOCI")	D. Accumulated Other Comprehensive Income (Loss) (“AOCI”) Comprehensive income combines net income (loss) and other comprehensive income items, which are reported as components of stockholders’ equity in the accompanying Consolidated Balance Sheets. Changes in each component of AOCI, net of tax, were as follows: Currency Pension and Other Total (In millions) Balance at September 30, 2023, attributable to Cabot Corporation $ ( 353 ) $ ( 9 ) $ ( 362 ) Other comprehensive income (loss) before reclassifications 62 — 62 Amounts reclassified from AOCI ( 1 ) — ( 1 ) Less: Other comprehensive income (loss) attributable to 4 — 4 Balance at December 31, 2023, attributable to Cabot Corporation $ ( 296 ) $ ( 9 ) $ ( 305 ) Other comprehensive income (loss) before reclassifications ( 15 ) — ( 15 ) Amounts reclassified from AOCI — ( 1 ) ( 1 ) Less: Other comprehensive income (loss) attributable to ( 4 ) — ( 4 ) Balance at March 31, 2024, attributable to Cabot Corporation $ ( 307 ) $ ( 10 ) $ ( 317 ) Other comprehensive income (loss) before reclassifications ( 66 ) — ( 66 ) Amounts reclassified from AOCI — — — Less: Other comprehensive income (loss) attributable to ( 1 ) — ( 1 ) Balance at June 30, 2024, attributable to Cabot Corporation $ ( 372 ) $ ( 10 ) $ ( 382 ) Currency Pension and Other Total (In millions) Balance at September 30, 2022, attributable to Cabot Corporation $ ( 429 ) $ ( 10 ) $ ( 439 ) Other comprehensive income (loss) before reclassifications 88 — 88 Amounts reclassified from AOCI ( 1 ) — ( 1 ) Less: Other comprehensive income (loss) attributable to 6 — 6 Balance at December 31, 2022, attributable to Cabot Corporation $ ( 348 ) $ ( 10 ) $ ( 358 ) Other comprehensive income (loss) before reclassifications 49 — 49 Amounts reclassified from AOCI ( 1 ) ( 1 ) ( 2 ) Less: Other comprehensive income (loss) attributable to 3 — 3 Balance at March 31, 2023, attributable to Cabot Corporation $ ( 303 ) $ ( 11 ) $ ( 314 ) Other comprehensive income (loss) before reclassifications ( 20 ) 1 ( 19 ) Amounts reclassified from AOCI ( 1 ) ( 1 ) ( 2 ) Less: Other comprehensive income (loss) attributable to ( 6 ) — ( 6 ) Balance at June 30, 2023, attributable to Cabot Corporation $ ( 318 ) $ ( 11 ) $ ( 329 ) The amounts reclassified out of AOCI and into the Consolidated Statements of Operations in each of the three and nine months ended June 30, 2024 and 2023 are as follows: Affected Line Item in the Consolidated Three Months Ended June 30 Nine Months Ended June 30 Statements of Operations 2024 2023 2024 2023 (In millions) Derivatives: net investment hedges (Gains) losses reclassified to interest Interest expense $ ( 1 ) $ ( 1 ) $ ( 4 ) $ ( 4 ) (Gains) losses excluded from effectiveness testing and amortized to interest expense Interest expense 1 — 2 1 Pension and other postretirement Amortization of actuarial losses and prior service cost (credit) Other income (expense) — ( 1 ) ( 1 ) ( 2 ) Total before tax $ — $ ( 2 ) $ ( 3 ) $ ( 5 )

Contingencies

Contingencies	9 Months Ended
	Jun. 30, 2024
Commitments and Contingencies Disclosure [Abstract]
Contingencies	E. Contingencies Respirator Liabilities Cabot has exposure in connection with a safety respiratory products business that a subsidiary acquired from American Optical Corporation (“AO”) in an April 1990 asset purchase transaction. The subsidiary manufactured respirators under the AO brand and disposed of that business in July 1995. In connection with its acquisition of the business, the subsidiary agreed, in certain circumstances, to assume a portion of AO’s liabilities, including costs of legal fees together with amounts paid in settlements and judgments, allocable to AO respiratory products used prior to the 1990 purchase by the Cabot subsidiary. In exchange for the subsidiary’s assumption of certain of AO’s respirator liabilities, AO agreed to provide to the subsidiary the benefits of: (i) AO’s insurance coverage for the period prior to the 1990 acquisition and (ii) a former owner’s indemnity of AO holding it harmless from any liability allocable to AO respiratory products used prior to May 1982. As more fully described in the 2023 10-K, the respirator liabilities generally involve claims for personal injury, including asbestosis, silicosis and coal worker’s pneumoconiosis, allegedly resulting from the use of respirators that are alleged to have been negligently designed and/or labeled. At no time did this respiratory product line represent a significant portion of the respirator market. In addition to Cabot’s subsidiary, other parties are responsible for significant portions of the costs of these respirator liabilities (as defined in the 2023 10-K, the “Payor Group”). Cabot has a reserve to cover its expected share of liabilities for pending and future respirator liability claims, which is included in Other liabilities and Accounts payable and accrued liabilities on the Consolidated Balance Sheets. The Company expects these liabilities to be incurred over a number of years. The reserve balance was $ 37 million and $ 38 million at June 30, 2024 and September 30, 2023, respectively. The Company’s current estimate of the cost of its share of pending and future respirator liability claims is based on facts and circumstances existing at this time, including the number and nature of the remaining claims. Developments that could affect the Company’s estimate include, but are not limited to, (i) significant changes in the number of future claims, (ii) changes in the rate of dismissals without payment of pending claims, (iii) significant changes in the average cost of resolving claims, including potential settlements of groups of claims, (iv) significant changes in the legal costs of defending these claims, (v) changes in the nature of claims received or changes in our assessment of the viability of these claims, (vi) trial and appellate outcomes, (vii) changes in the law and procedure applicable to these claims, (viii) the financial viability of the parties that contribute to the payment of respirator claims, (ix) exhaustion or changes in the recoverability of the insurance coverage maintained by certain members of the Payor Group, or a change in the availability of the indemnity provided by a former owner of AO, (x) changes in the allocation of costs among the various parties paying legal and settlement costs, and (xi) a determination that the assumptions that were used to estimate Cabot’s share of liability are no longer reasonable. The Company cannot determine the impact of these potential developments on its current estimate of its share of liability for existing and future claims. Because reserves are limited to amounts that are probable and estimable as of a relevant measurement date, and there is inherent difficulty in projecting the impact of potential developments on Cabot’s share of liability for these existing and future claims, it is reasonably possible that the liabilities for existing and future claims could change in the near term and that change could be material. Other Matters The Company has various other lawsuits, claims and contingent liabilities arising in the ordinary course of its business and with respect to its divested businesses. The Company does not believe that any of these matters will have a material adverse effect on its financial position; however, litigation is inherently unpredictable. Cabot could incur judgments, enter into settlements or revise its expectations regarding the outcome of certain matters, and such developments could have a material impact on its results of operations in the period in which the amounts are accrued or its cash flows in the period in which the amounts are paid.

Income Tax

Income Tax	9 Months Ended
	Jun. 30, 2024
Income Tax Disclosure [Abstract]
Income Tax	F. Income Tax Effective Tax Rate Three Months Ended June 30 Nine Months Ended June 30 2024 2023 2024 2023 (Dollars in millions) (Provision) benefit for income taxes $ ( 40 ) $ ( 41 ) $ ( 121 ) $ ( 90 ) Effective tax rate 25 % 32 % 31 % 28 % For the three and nine months ended June 30, 2024 , the (Provision) benefit for income taxes included a net discrete tax benefit of $ 1 million and an expense of $ 14 million, respectively. The net discrete tax expense of $ 14 million is primarily comprised of additional accruals and corresponding interest of uncertain tax positions. For the three and nine months ended June 30, 2023 , the (Provision) benefit for income taxes included a net discrete tax expense of $ 2 million and $ 3 million, respectively. Income tax in Interim Periods The Company records its tax provision or benefit on an interim basis using an estimated annual effective tax rate. This rate is applied to the current period ordinary income or loss to determine the income tax provision or benefit allocated to the interim period. The income tax effects of unusual or infrequent items are excluded from the estimated annual effective tax rate and are recognized in the impacted interim period. Losses from jurisdictions for which no benefit can be recognized are excluded from the overall computations of the estimated annual effective tax rate and a separate estimated annual effective tax rate is computed and applied to ordinary income or loss in the loss jurisdiction. Valuation allowances are provided against the future tax benefits that arise from the deferred tax assets in jurisdictions for which the Company expects that no benefit can be recognized. The estimated annual effective tax rate may be significantly impacted by nondeductible expenses and the Company’s projected earnings mix by tax jurisdiction. Adjustments to the estimated annual effective income tax rate are recognized in the period when such estimates are revised. Uncertainties Cabot and certain subsidiaries are under audit in a number of jurisdictions. In addition, certain statutes of limitations are scheduled to expire in the near future. It is reasonably possible that a change in the unrecognized tax benefits may also occur within the next twelve months related to the settlement of one or more of these audits or the lapse of applicable statutes of limitations. However, an estimated range of the impact on the unrecognized tax benefits cannot be quantified at this time. Cabot files U.S. federal and state and non-U.S. income tax returns in jurisdictions with varying statutes of limitations. The 2021 through 2023 tax years generally remain subject to examination by the IRS and various tax years from 2018 through 2023 remain subject to examination by the respective state tax authorities. In foreign jurisdictions, various tax years from 2006 through 2023 remain subject to examination by their respective tax authorities. During each of the three and nine months ended June 30, 2024 , Cabot released uncertain tax positions of nil and $ 1 million, respectively, due to the expiration of statutes of limitations in various jurisdictions. During each of the three and nine months ended June 30, 2023 , Cabot released uncertain tax positions of nil and $ 1 million, respectively, due to the expiration of statutes of limitations in various jurisdictions.

Earnings Per Share

Earnings Per Share	9 Months Ended
	Jun. 30, 2024
Earnings Per Share [Abstract]
Earnings Per Share	G. Earnings Per Share The following tables summarize the components of the basic and diluted earnings (loss) per common share (“EPS”) computations: Three Months Ended June 30 Nine Months Ended June 30 2024 2023 2024 2023 (In millions, except per share amounts) Basic EPS: Net income (loss) attributable to Cabot $ 109 $ 82 $ 243 $ 211 Less: Dividends and dividend equivalents — — — 1 Less: Undistributed earnings allocated to (1) 1 1 3 3 Earnings (loss) allocated to common $ 108 $ 81 $ 240 $ 207 Weighted average common shares and 55.9 57.3 56.2 57.5 Less: Participating securities (1) 0.8 1.2 0.9 1.3 Adjusted weighted average common 55.1 56.1 55.3 56.2 Earnings (loss) per common share - basic: $ 1.96 $ 1.44 $ 4.34 $ 3.68 Diluted EPS: Earnings (loss) allocated to common $ 108 $ 81 $ 240 $ 207 Plus: Earnings allocated to 1 1 3 4 Less: Adjusted earnings allocated to (2) 1 1 3 4 Earnings (loss) allocated to common $ 108 $ 81 $ 240 $ 207 Adjusted weighted average common 55.1 56.1 55.3 56.2 Effect of dilutive securities: Common shares issuable (3) 0.6 0.4 0.5 0.5 Adjusted weighted average common 55.7 56.5 55.8 56.7 Earnings (loss) per common share - diluted: $ 1.94 $ 1.43 $ 4.30 $ 3.65 (1) Participating securities consist of shares underlying unvested time-based restricted stock units (the "TSUs"), earned and unvested performance-based restricted stock units (the "PSUs", and referred to in this note collectively with the TSUs as the "RSUs"), stock units accounted for under the Supplemental 401(k) Plan portion of the Company’s Deferred Compensation and Supplemental Retirement Plan, and stock units and phantom stock units accounted for under the Company’s Non-Employee Directors’ Deferral Plan. The holders of RSUs are entitled to receive dividend equivalents, payable in cash, to the extent dividends are paid on the outstanding shares of Common Stock, and equal in value to the dividends that would have been paid in respect of the Common Stock underlying the RSU. The accounts of holders of stock units and phantom stock units are credited with dividend equivalents, which are payable, in stock or cash, as the case may be, with the distribution of account balances. Undistributed earnings are the earnings which remain after dividends declared during the period are assumed to be distributed to the common and participating stockholders. Undistributed earnings are allocated to common and participating stockholders on the same basis as dividend distributions. The calculation of undistributed earnings is as follows: Three Months Ended June 30 Nine Months Ended June 30 2024 2023 2024 2023 (In millions) Calculation of undistributed earnings (loss): Net income (loss) attributable to Cabot Corporation $ 109 $ 82 $ 243 $ 211 Less: Dividends declared on common stock 24 23 69 64 Less: Dividends declared on participating — — — 1 Undistributed earnings (loss) $ 85 $ 59 $ 174 $ 146 Allocation of undistributed earnings (loss): Undistributed earnings (loss) allocated to $ 84 $ 58 $ 171 $ 143 Undistributed earnings allocated to 1 1 3 3 Undistributed earnings (loss) $ 85 $ 59 $ 174 $ 146 (2) Undistributed earnings are adjusted for the assumed distribution of dividends to the dilutive securities, which are described in (3) below, and then reallocated to participating securities. (3) Represents incremental shares of common stock from the assumed exercise of stock options issued under Cabot’s equity incentive plans. For the three and nine months ended June 30, 2024 , nil and 209,478 incremental shares of common stock, respectively, were excluded from the calculation of diluted earnings per share because the inclusion of these shares would have been antidilutive. For the three and nine months ended June 30, 2023 , 156,550 and 133,039 incremental shares of common stock, respectively, were excluded from the calculation of diluted earnings per share because the inclusion of these shares would have been antidilutive.

Restructuring

Restructuring	9 Months Ended
	Jun. 30, 2024
Restructuring and Related Activities [Abstract]
Restructuring	H. Restructuring 2024 Reorganizations During the first quarter of fiscal 2024, the Company initiated restructuring activities in both its Reinforcement Materials segment (“RM Plan”) and its Performance Chemicals segment (“PC Plan”). Under the RM Plan, the Company closed its reinforcing carbons unit at the facility in Tianjin, China that the Company acquired from Tokai Carbon Group in February 2022, consolidating its reinforcing carbons operations and reducing ongoing operational costs. Under the PC Plan, the Company has temporarily idled its aerogel manufacturing plant in Frankfurt, Germany and reorganized certain positions within the Performance Chemicals segment to reduce operating costs. Although the Frankfurt facility is idled, the Company continues its efforts to commercialize aerogel for use in thermal insulation for electric vehicles. During the three and nine months ended June 30, 2024, the Company recorded charges of $ 1 million and $ 13 million, respectively, primarily for severance related costs and accelerated depreciation as part of these plans. The Company expects to record additional restructuring charges of $ 1 million related to these plans through fiscal 2025. Cabot’s restructuring activities were recorded in the Consolidated Statements of Operations for the three and nine months ended June 30, 2024 and 2023 as follows: Three Months Ended June 30 Nine Months Ended June 30 2024 2023 2024 2023 (In millions) Cost of sales $ 1 $ — $ 12 $ — Selling and administrative expenses — — 1 — Total $ 1 $ — $ 13 $ — Details of all restructuring activities and the related reserves during the three and nine months ended June 30, 2024 are as follows: Severance Accelerated Depreciation on Assets Other Total (In millions) Reserve at September 30, 2023 $ — $ — $ — $ — Charges 3 6 — 9 Cost charged against assets — ( 6 ) — ( 6 ) Cash paid ( 1 ) — — ( 1 ) Reserve at December 31, 2023 $ 2 $ — $ — $ 2 Charges 2 — 1 3 Cash paid ( 1 ) — — ( 1 ) Reserve at March 31, 2024 $ 3 $ — $ 1 $ 4 Charges — — 1 1 Cash paid ( 2 ) — ( 1 ) ( 3 ) Reserve at June 30, 2024 $ 1 $ — $ 1 $ 2 Cabot’s severance and employee benefit reserves are reflected in Accounts payable and accrued liabilities on the Company’s Consolidated Balance Sheets.

Financial Instruments and Fair

Financial Instruments and Fair Value Measurements	9 Months Ended
	Jun. 30, 2024
Fair Value Disclosures [Abstract]
Financial Instruments and Fair Value Measurements	I. Financial Instruments and Fair Value Measurements The FASB authoritative guidance on fair value measurements defines fair value, provides a framework for measuring fair value, and requires certain disclosures about fair value measurements. The required disclosures focus on the inputs used to measure fair value. The guidance establishes the following hierarchy for categorizing these inputs: Level 1 — Quoted market prices in active markets for identical assets or liabilities Level 2 — Significant other observable inputs (e.g., quoted prices for similar items in active markets, quoted prices for identical or similar items in markets that are not active, inputs other than quoted prices that are observable such as interest rate and yield curves, and market-corroborated inputs) Level 3 — Significant unobservable inputs There were no transfers of financial assets or liabilities measured at fair value between Level 1 and Level 2 and there were no Level 3 investments during the first nine months of either fiscal 2024 or 2023. At June 30, 2024 and September 30, 2023, the fair values of cash and cash equivalents, accounts and notes receivable, accounts payable and accrued liabilities, and short-term borrowings and variable rate debt approximated their carrying values due to the short-term nature of these instruments. Cash and cash equivalents are classified as Level 1 within the fair value hierarchy. At June 30, 2024 and September 30, 2023, Cabot had derivatives relating to foreign currency risks, including a net investment hedge and forward foreign currency contracts, carried at fair value. At June 30, 2024 and September 30, 2023 , the fair value of these derivatives was a net asset of $ 9 million and $ 12 million, respectively, and was included in Prepaid expenses and other current assets, Accounts payable and accrued liabilities, and Other assets on the Consolidated Balance Sheets. These derivatives are classified as Level 2 instruments within the fair value hierarchy as the fair value determination was based on observable inputs. At June 30, 2024 and September 30, 2023, the fair value of guaranteed investment contracts included in Other assets on the Consolidated Balance Sheets was $ 8 million . Guaranteed investment contracts were classified as Level 2 instruments within the fair value hierarchy as the fair value determination was based on other observable inputs. The carrying value and fair value of the long-term fixed rate debt w ere $ 1.07 billion and $ 1.04 billion, res pectively, as of June 30, 2024 , and $ 1.08 billion and $ 1.04 billion, respectively, as of September 30, 2023 . The fair values of Cabot’s fixed rate long-term debt are estimated based on comparable quoted market prices at the respective period ends. The carrying amounts of Cabot’s floating rate long-term debt and finance and operating lease obligations approximate their fair values. All such measurements are based on observable inputs and are classified as Level 2 within the fair value hierarchy. The valuation technique used is the discounted cash flow model.

Supplier Financing Programs

Supplier Financing Programs	9 Months Ended
	Jun. 30, 2024
Payables and Accruals [Abstract]
Supplier Financing Programs	J. Supplier Financing Programs The Company maintains supply chain finance agreements with third-party financial institutions. These agreements allow the Company’s participating suppliers to sell their receivables to such third-party financial institutions to receive payment earlier than the negotiated commercial terms between the supplier and the Company. Such sales are at the sole discretion of the supplier, and on terms and conditions that are negotiated between the supplier and the respective financial institution. The terms and conditions of the supplier invoice, including payment terms and amounts due, are not impacted by a supplier’s participation in the program. Pursuant to the supply chain finance agreements, the Company has agreed to pay financial institutions on the original due date of the applicable invoice. There are no guarantees associated with these programs. The Company's outstanding payment obligations to financial institutions related to supplier financing programs were $ 17 million at both June 30, 2024 and September 30, 2023 , and are included within Accounts payable and accrued liabilities on the Consolidated Balance Sheets.

Financial Information by Segmen

Financial Information by Segment	9 Months Ended
	Jun. 30, 2024
Segment Reporting [Abstract]
Financial Information by Segment	K. Financial Information by Segment The Company identifies a product line as an operating segment if: i) it engages in business activities from which it may earn revenues and incur expenses; ii) its operating results are regularly reviewed by the Chief Operating Decision Maker (“CODM”), who is Cabot’s President and Chief Executive Officer, to make decisions about resources to be allocated to the segment and assess its performance; and iii) it has available discrete financial information. The CODM reviews financial information at the operating segment level to allocate resources and to assess the operating results and financial performance for each operating segment. Operating segments are aggregated into a reportable segment if the operating segments are determined to have similar economic characteristics and if the operating segments are similar in the following areas: i) nature of products and services; ii) nature of production processes; iii) type or class of customer for their products and services; iv) methods used to distribute the products or provide services; and v) if applicable, the nature of the regulatory environment. The Company has two reportable segments: Reinforcement Materials and Performance Chemicals. The Reinforcement Materials segment combines the reinforcing carbons and engineered elastomer composites product lines. The Performance Chemicals segment aggregates the specialty carbons, specialty compounds, fumed metal oxides, battery materials, inkjet colorants and aerogel product lines. Income (loss) before income taxes (“Segment EBIT”) is presented for each reportable segment in the table below. Segment EBIT excludes Interest expense, General unallocated income (expense), Unallocated corporate costs and Certain items, meaning items management does not consider representative of on-going operating segment results. In addition, Segment EBIT includes Equity in earnings of affiliated companies, net of tax, royalties, Net income attributable to noncontrolling interests, net of tax, and discounting charges for certain Notes receivable. Financial information by reportable segment is as follows: Reinforcement Performance Segment Unallocated (1) Consolidated (In millions) Three Months Ended June 30, 2024 Revenues from external customers (2) $ 649 $ 332 $ 981 $ 35 $ 1,016 Income (loss) before income taxes (3) $ 136 $ 55 $ 191 $ ( 33 ) $ 158 Three Months Ended June 30, 2023 Revenues from external customers (2) $ 624 $ 307 $ 931 $ 37 $ 968 Income (loss) before income taxes (3) $ 132 $ 32 $ 164 $ ( 34 ) $ 130 Nine Months Ended June 30, 2024 Revenues from external customers (2) $ 1,966 $ 928 $ 2,894 $ 99 $ 2,993 Income (loss) before income taxes (3) $ 414 $ 120 $ 534 $ ( 140 ) $ 394 Nine Months Ended June 30, 2023 Revenues from external customers (2) $ 1,939 $ 919 $ 2,858 $ 108 $ 2,966 Income (loss) before income taxes (3) $ 348 $ 89 $ 437 $ ( 113 ) $ 324 (1) Unallocated and Other includes certain items and eliminations necessary to reflect management’s reporting of operating segment results. These items are reflective of the segment reporting presented to the CODM. (2) Consolidated Total Revenues from external customers reconciles to Net sales and other operating revenues on the Consolidated Statements of Operations. Revenues from external customers that are categorized as Unallocated and Other reflects external shipping and handling fees, royalties, the impact of unearned revenue, discounting charges for certain Notes receivable, and other by-product revenue. Details are provided in the table below: Three Months Ended June 30 Nine Months Ended June 30 2024 2023 2024 2023 (In millions) Shipping and handling fees $ 31 $ 31 $ 93 $ 100 Other 4 6 6 8 Total $ 35 $ 37 $ 99 $ 108 (3) Consolidated Total Income (loss) before income taxes reconciles to Income (loss) before income taxes and equity in earnings of affiliated companies on the Consolidated Statements of Operations. Income (loss) before income taxes that are categorized as Unallocated and Other includes: Three Months Ended June 30 Nine Months Ended June 30 2024 2023 2024 2023 (In millions) Interest expense $ ( 19 ) $ ( 24 ) $ ( 62 ) $ ( 69 ) Certain items (a) Argentina controlled currency devaluation and other losses (Note B) ( 2 ) — ( 43 ) — Global restructuring activities (Note H) ( 1 ) — ( 13 ) — Acquisition and integration-related charges — ( 1 ) — ( 2 ) Legal and environmental matters and reserves — — ( 1 ) ( 2 ) Gain on sale of land — — — 1 Loss on sale of business — — — ( 3 ) Other 1 — 1 ( 1 ) Total certain items ( 2 ) ( 1 ) ( 56 ) ( 7 ) Unallocated corporate costs (b) ( 16 ) ( 11 ) ( 51 ) ( 42 ) General unallocated income (expense) (c) 6 3 34 9 Less: Equity in earnings of affiliated companies, net (d) 2 1 5 4 Total $ ( 33 ) $ ( 34 ) $ ( 140 ) $ ( 113 ) (a) Certain items are items of expense and income that management does not consider representative of the Company’s fundamental on-going segment results and they are, therefore, excluded from Segment EBIT. (b) Unallocated corporate costs are costs that are not controlled by the segments and primarily benefit corporate interests. (c) General unallocated income (expense) consists of gains (losses) arising from foreign currency transactions, net of other foreign currency risk management activities, Interest and dividend income, the profit or loss related to the corporate adjustment for unearned revenue and unrealized holding gains (losses) for investments. This does not include items of income or expense that are separately treated as Certain items. (d) Equity in earnings of affiliated companies, net of tax, is included in Segment EBIT and is removed in Unallocated and other to reconcile to Income (loss) from operations before income taxes and equity in earnings from affiliated companies. The Company’s segments operate globally. In addition to presenting Revenue from external customers by reportable segment, the following tables further disaggregate Revenues from external customers by geographic region. Three Months Ended June 30, 2024 Reinforcement Performance Consolidated Total (In millions) Americas $ 265 $ 103 $ 368 Asia Pacific 245 132 377 Europe, Middle East and Africa 139 97 236 Segment revenues from external customers 649 332 981 Unallocated and other 35 Net sales and other operating revenues $ 1,016 Three Months Ended June 30, 2023 Reinforcement Performance Consolidated Total (In millions) Americas $ 260 $ 94 $ 354 Asia Pacific 234 119 353 Europe, Middle East and Africa 130 94 224 Segment revenues from external customers 624 307 931 Unallocated and other 37 Net sales and other operating revenues $ 968 Nine Months Ended June 30, 2024 Reinforcement Performance Consolidated Total (In millions) Americas $ 793 $ 284 $ 1,077 Asia Pacific 760 372 1,132 Europe, Middle East and Africa 413 272 685 Segment revenues from external customers 1,966 928 2,894 Unallocated and other 99 Net sales and other operating revenues $ 2,993 Nine Months Ended June 30, 2023 Reinforcement Performance Consolidated Total (In millions) Americas $ 781 $ 283 $ 1,064 Asia Pacific 752 368 1,120 Europe, Middle East and Africa 406 268 674 Segment revenues from external customers 1,939 919 2,858 Unallocated and other 108 Net sales and other operating revenues $ 2,966

Subsequent Event

Subsequent Event	9 Months Ended
	Jun. 30, 2024
Subsequent Events [Abstract]
Subsequent Event	L. Subsequent Event On July 19, 2024, Cabot entered into agreements to purchase certain assets and to license the related technology, which the Company expects to use in its manufacturing of certain products for its Battery Materials product line. Under these agreements, the Company will pay $ 27 million at closing, which is expected to occur in the first quarter of fiscal 2025.

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	9 Months Ended
	Jun. 30, 2024
Accounting Policies [Abstract]
Recently Adopted Accounting Standards	Recently Adopted Accounting Standards In November 2022, the Financial Accounting Standards Board (“FASB”) issued a new standard on the disclosure of supplier financing programs. The new standard requires qualitative and quantitative disclosures as to the nature and potential magnitude of such programs in addition to program activity and changes for the periods presented. The Company adopted this standard on October 1, 2023. See Note J for disclosures related to the Company's supplier financing programs. The adoption of this standard did not have a material impact on the Company's Consolidated Financial Statements.
Recent Accounting Pronouncements	Recent Accounting Pronouncements 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 November 2023, the FASB issued a new standard, Improvement to Reportable Segment Disclosures. The new guidance enhances the disclosure of significant reportable segment expenses. The new standard is effective for the Company’s fiscal years beginning 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. 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.

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	9 Months Ended
	Jun. 30, 2024
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Changes in Balances	The carrying amount of goodwill attributable to each reportable segment and the changes in those balances during the nine months ended June 30, 2024 are as follows: Reinforcement Performance Total (In millions) Balance at September 30, 2023 $ 51 $ 83 $ 134 Foreign currency impact ( 2 ) — ( 2 ) Balance at June 30, 2024 $ 49 $ 83 $ 132
Schedule of Intangible Assets	The following table provides information regarding the Company’s intangible assets: June 30, 2024 September 30, 2023 Gross Accumulated Net Gross Accumulated Net (In millions) Intangible assets with finite lives Developed technologies $ 33 $ ( 11 ) $ 22 $ 34 $ ( 10 ) $ 24 Trademarks 2 ( 1 ) 1 2 ( 1 ) 1 Customer relationships 63 ( 31 ) 32 65 ( 30 ) 35 Total intangible assets $ 98 $ ( 43 ) $ 55 $ 101 $ ( 41 ) $ 60

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Loss) ("AOCI") (Tables)	9 Months Ended
	Jun. 30, 2024
Equity [Abstract]
Changes in Each Component of AOCI, Net of Tax	Changes in each component of AOCI, net of tax, were as follows: Currency Pension and Other Total (In millions) Balance at September 30, 2023, attributable to Cabot Corporation $ ( 353 ) $ ( 9 ) $ ( 362 ) Other comprehensive income (loss) before reclassifications 62 — 62 Amounts reclassified from AOCI ( 1 ) — ( 1 ) Less: Other comprehensive income (loss) attributable to 4 — 4 Balance at December 31, 2023, attributable to Cabot Corporation $ ( 296 ) $ ( 9 ) $ ( 305 ) Other comprehensive income (loss) before reclassifications ( 15 ) — ( 15 ) Amounts reclassified from AOCI — ( 1 ) ( 1 ) Less: Other comprehensive income (loss) attributable to ( 4 ) — ( 4 ) Balance at March 31, 2024, attributable to Cabot Corporation $ ( 307 ) $ ( 10 ) $ ( 317 ) Other comprehensive income (loss) before reclassifications ( 66 ) — ( 66 ) Amounts reclassified from AOCI — — — Less: Other comprehensive income (loss) attributable to ( 1 ) — ( 1 ) Balance at June 30, 2024, attributable to Cabot Corporation $ ( 372 ) $ ( 10 ) $ ( 382 ) Currency Pension and Other Total (In millions) Balance at September 30, 2022, attributable to Cabot Corporation $ ( 429 ) $ ( 10 ) $ ( 439 ) Other comprehensive income (loss) before reclassifications 88 — 88 Amounts reclassified from AOCI ( 1 ) — ( 1 ) Less: Other comprehensive income (loss) attributable to 6 — 6 Balance at December 31, 2022, attributable to Cabot Corporation $ ( 348 ) $ ( 10 ) $ ( 358 ) Other comprehensive income (loss) before reclassifications 49 — 49 Amounts reclassified from AOCI ( 1 ) ( 1 ) ( 2 ) Less: Other comprehensive income (loss) attributable to 3 — 3 Balance at March 31, 2023, attributable to Cabot Corporation $ ( 303 ) $ ( 11 ) $ ( 314 ) Other comprehensive income (loss) before reclassifications ( 20 ) 1 ( 19 ) Amounts reclassified from AOCI ( 1 ) ( 1 ) ( 2 ) Less: Other comprehensive income (loss) attributable to ( 6 ) — ( 6 ) Balance at June 30, 2023, attributable to Cabot Corporation $ ( 318 ) $ ( 11 ) $ ( 329 )
Amounts Reclassified Out of AOCI	The amounts reclassified out of AOCI and into the Consolidated Statements of Operations in each of the three and nine months ended June 30, 2024 and 2023 are as follows: Affected Line Item in the Consolidated Three Months Ended June 30 Nine Months Ended June 30 Statements of Operations 2024 2023 2024 2023 (In millions) Derivatives: net investment hedges (Gains) losses reclassified to interest Interest expense $ ( 1 ) $ ( 1 ) $ ( 4 ) $ ( 4 ) (Gains) losses excluded from effectiveness testing and amortized to interest expense Interest expense 1 — 2 1 Pension and other postretirement Amortization of actuarial losses and prior service cost (credit) Other income (expense) — ( 1 ) ( 1 ) ( 2 ) Total before tax $ — $ ( 2 ) $ ( 3 ) $ ( 5 )

Income Tax (Tables)

Income Tax (Tables)	9 Months Ended
	Jun. 30, 2024
Income Tax Disclosure [Abstract]
Effective Tax Rate	Effective Tax Rate Three Months Ended June 30 Nine Months Ended June 30 2024 2023 2024 2023 (Dollars in millions) (Provision) benefit for income taxes $ ( 40 ) $ ( 41 ) $ ( 121 ) $ ( 90 ) Effective tax rate 25 % 32 % 31 % 28 %

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Jun. 30, 2024
Earnings Per Share [Abstract]
Components of Basic and Diluted Earnings (Loss) Per Common Share (EPS)	The following tables summarize the components of the basic and diluted earnings (loss) per common share (“EPS”) computations: Three Months Ended June 30 Nine Months Ended June 30 2024 2023 2024 2023 (In millions, except per share amounts) Basic EPS: Net income (loss) attributable to Cabot $ 109 $ 82 $ 243 $ 211 Less: Dividends and dividend equivalents — — — 1 Less: Undistributed earnings allocated to (1) 1 1 3 3 Earnings (loss) allocated to common $ 108 $ 81 $ 240 $ 207 Weighted average common shares and 55.9 57.3 56.2 57.5 Less: Participating securities (1) 0.8 1.2 0.9 1.3 Adjusted weighted average common 55.1 56.1 55.3 56.2 Earnings (loss) per common share - basic: $ 1.96 $ 1.44 $ 4.34 $ 3.68 Diluted EPS: Earnings (loss) allocated to common $ 108 $ 81 $ 240 $ 207 Plus: Earnings allocated to 1 1 3 4 Less: Adjusted earnings allocated to (2) 1 1 3 4 Earnings (loss) allocated to common $ 108 $ 81 $ 240 $ 207 Adjusted weighted average common 55.1 56.1 55.3 56.2 Effect of dilutive securities: Common shares issuable (3) 0.6 0.4 0.5 0.5 Adjusted weighted average common 55.7 56.5 55.8 56.7 Earnings (loss) per common share - diluted: $ 1.94 $ 1.43 $ 4.30 $ 3.65 (1) Participating securities consist of shares underlying unvested time-based restricted stock units (the "TSUs"), earned and unvested performance-based restricted stock units (the "PSUs", and referred to in this note collectively with the TSUs as the "RSUs"), stock units accounted for under the Supplemental 401(k) Plan portion of the Company’s Deferred Compensation and Supplemental Retirement Plan, and stock units and phantom stock units accounted for under the Company’s Non-Employee Directors’ Deferral Plan. The holders of RSUs are entitled to receive dividend equivalents, payable in cash, to the extent dividends are paid on the outstanding shares of Common Stock, and equal in value to the dividends that would have been paid in respect of the Common Stock underlying the RSU. The accounts of holders of stock units and phantom stock units are credited with dividend equivalents, which are payable, in stock or cash, as the case may be, with the distribution of account balances.
Calculation of Undistributed Earnings	Undistributed earnings are the earnings which remain after dividends declared during the period are assumed to be distributed to the common and participating stockholders. Undistributed earnings are allocated to common and participating stockholders on the same basis as dividend distributions. The calculation of undistributed earnings is as follows: Three Months Ended June 30 Nine Months Ended June 30 2024 2023 2024 2023 (In millions) Calculation of undistributed earnings (loss): Net income (loss) attributable to Cabot Corporation $ 109 $ 82 $ 243 $ 211 Less: Dividends declared on common stock 24 23 69 64 Less: Dividends declared on participating — — — 1 Undistributed earnings (loss) $ 85 $ 59 $ 174 $ 146 Allocation of undistributed earnings (loss): Undistributed earnings (loss) allocated to $ 84 $ 58 $ 171 $ 143 Undistributed earnings allocated to 1 1 3 3 Undistributed earnings (loss) $ 85 $ 59 $ 174 $ 146 (2) Undistributed earnings are adjusted for the assumed distribution of dividends to the dilutive securities, which are described in (3) below, and then reallocated to participating securities. (3) Represents incremental shares of common stock from the assumed exercise of stock options issued under Cabot’s equity incentive plans. For the three and nine months ended June 30, 2024 , nil and 209,478 incremental shares of common stock, respectively, were excluded from the calculation of diluted earnings per share because the inclusion of these shares would have been antidilutive. For the three and nine months ended June 30, 2023 , 156,550 and 133,039 incremental shares of common stock, respectively, were excluded from the calculation of diluted earnings per share because the inclusion of these shares would have been antidilutive.

Restructuring (Tables)

Restructuring (Tables)	9 Months Ended
	Jun. 30, 2024
Restructuring and Related Activities [Abstract]
Recorded Restructuring Activities	Cabot’s restructuring activities were recorded in the Consolidated Statements of Operations for the three and nine months ended June 30, 2024 and 2023 as follows: Three Months Ended June 30 Nine Months Ended June 30 2024 2023 2024 2023 (In millions) Cost of sales $ 1 $ — $ 12 $ — Selling and administrative expenses — — 1 — Total $ 1 $ — $ 13 $ —
Restructuring Activities and Related Reserves	Details of all restructuring activities and the related reserves during the three and nine months ended June 30, 2024 are as follows: Severance Accelerated Depreciation on Assets Other Total (In millions) Reserve at September 30, 2023 $ — $ — $ — $ — Charges 3 6 — 9 Cost charged against assets — ( 6 ) — ( 6 ) Cash paid ( 1 ) — — ( 1 ) Reserve at December 31, 2023 $ 2 $ — $ — $ 2 Charges 2 — 1 3 Cash paid ( 1 ) — — ( 1 ) Reserve at March 31, 2024 $ 3 $ — $ 1 $ 4 Charges — — 1 1 Cash paid ( 2 ) — ( 1 ) ( 3 ) Reserve at June 30, 2024 $ 1 $ — $ 1 $ 2

Financial Information by Segm_2

Financial Information by Segment (Tables)	9 Months Ended
	Jun. 30, 2024
Segment Reporting [Abstract]
Financial Information by Reportable Segment	Financial information by reportable segment is as follows: Reinforcement Performance Segment Unallocated (1) Consolidated (In millions) Three Months Ended June 30, 2024 Revenues from external customers (2) $ 649 $ 332 $ 981 $ 35 $ 1,016 Income (loss) before income taxes (3) $ 136 $ 55 $ 191 $ ( 33 ) $ 158 Three Months Ended June 30, 2023 Revenues from external customers (2) $ 624 $ 307 $ 931 $ 37 $ 968 Income (loss) before income taxes (3) $ 132 $ 32 $ 164 $ ( 34 ) $ 130 Nine Months Ended June 30, 2024 Revenues from external customers (2) $ 1,966 $ 928 $ 2,894 $ 99 $ 2,993 Income (loss) before income taxes (3) $ 414 $ 120 $ 534 $ ( 140 ) $ 394 Nine Months Ended June 30, 2023 Revenues from external customers (2) $ 1,939 $ 919 $ 2,858 $ 108 $ 2,966 Income (loss) before income taxes (3) $ 348 $ 89 $ 437 $ ( 113 ) $ 324 (1) Unallocated and Other includes certain items and eliminations necessary to reflect management’s reporting of operating segment results. These items are reflective of the segment reporting presented to the CODM. (2) Consolidated Total Revenues from external customers reconciles to Net sales and other operating revenues on the Consolidated Statements of Operations. Revenues from external customers that are categorized as Unallocated and Other reflects external shipping and handling fees, royalties, the impact of unearned revenue, discounting charges for certain Notes receivable, and other by-product revenue. Details are provided in the table below: Three Months Ended June 30 Nine Months Ended June 30 2024 2023 2024 2023 (In millions) Shipping and handling fees $ 31 $ 31 $ 93 $ 100 Other 4 6 6 8 Total $ 35 $ 37 $ 99 $ 108 (3) Consolidated Total Income (loss) before income taxes reconciles to Income (loss) before income taxes and equity in earnings of affiliated companies on the Consolidated Statements of Operations. Income (loss) before income taxes that are categorized as Unallocated and Other includes: Three Months Ended June 30 Nine Months Ended June 30 2024 2023 2024 2023 (In millions) Interest expense $ ( 19 ) $ ( 24 ) $ ( 62 ) $ ( 69 ) Certain items (a) Argentina controlled currency devaluation and other losses (Note B) ( 2 ) — ( 43 ) — Global restructuring activities (Note H) ( 1 ) — ( 13 ) — Acquisition and integration-related charges — ( 1 ) — ( 2 ) Legal and environmental matters and reserves — — ( 1 ) ( 2 ) Gain on sale of land — — — 1 Loss on sale of business — — — ( 3 ) Other 1 — 1 ( 1 ) Total certain items ( 2 ) ( 1 ) ( 56 ) ( 7 ) Unallocated corporate costs (b) ( 16 ) ( 11 ) ( 51 ) ( 42 ) General unallocated income (expense) (c) 6 3 34 9 Less: Equity in earnings of affiliated companies, net (d) 2 1 5 4 Total $ ( 33 ) $ ( 34 ) $ ( 140 ) $ ( 113 ) (a) Certain items are items of expense and income that management does not consider representative of the Company’s fundamental on-going segment results and they are, therefore, excluded from Segment EBIT. (b) Unallocated corporate costs are costs that are not controlled by the segments and primarily benefit corporate interests. (c) General unallocated income (expense) consists of gains (losses) arising from foreign currency transactions, net of other foreign currency risk management activities, Interest and dividend income, the profit or loss related to the corporate adjustment for unearned revenue and unrealized holding gains (losses) for investments. This does not include items of income or expense that are separately treated as Certain items. (d) Equity in earnings of affiliated companies, net of tax, is included in Segment EBIT and is removed in Unallocated and other to reconcile to Income (loss) from operations before income taxes and equity in earnings from affiliated companies.
Revenues from External Customers by Geographic Region	The Company’s segments operate globally. In addition to presenting Revenue from external customers by reportable segment, the following tables further disaggregate Revenues from external customers by geographic region. Three Months Ended June 30, 2024 Reinforcement Performance Consolidated Total (In millions) Americas $ 265 $ 103 $ 368 Asia Pacific 245 132 377 Europe, Middle East and Africa 139 97 236 Segment revenues from external customers 649 332 981 Unallocated and other 35 Net sales and other operating revenues $ 1,016 Three Months Ended June 30, 2023 Reinforcement Performance Consolidated Total (In millions) Americas $ 260 $ 94 $ 354 Asia Pacific 234 119 353 Europe, Middle East and Africa 130 94 224 Segment revenues from external customers 624 307 931 Unallocated and other 37 Net sales and other operating revenues $ 968 Nine Months Ended June 30, 2024 Reinforcement Performance Consolidated Total (In millions) Americas $ 793 $ 284 $ 1,077 Asia Pacific 760 372 1,132 Europe, Middle East and Africa 413 272 685 Segment revenues from external customers 1,966 928 2,894 Unallocated and other 99 Net sales and other operating revenues $ 2,993 Nine Months Ended June 30, 2023 Reinforcement Performance Consolidated Total (In millions) Americas $ 781 $ 283 $ 1,064 Asia Pacific 752 368 1,120 Europe, Middle East and Africa 406 268 674 Segment revenues from external customers 1,939 919 2,858 Unallocated and other 108 Net sales and other operating revenues $ 2,966

Significant Accounting Polici_3

Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Jun. 30, 2024	Mar. 31, 2024	Dec. 31, 2023	Jun. 30, 2024
Other Income (Expense) [Member]
Significant Accounting Policies [Line Items]
Investment income (loss)	$ 16			$ 16
Other Income (Expense) [Member] | Revaluation of Non-functional Currency [Member]
Significant Accounting Policies [Line Items]
Foreign exchange losses	(2)			$ (42)
Other Income (Expense) [Member] | Single Devaluation Action [Member]
Significant Accounting Policies [Line Items]
Foreign exchange losses			$ (33)
BOPREAL Bonds [Member]
Significant Accounting Policies [Line Items]
Foreign exchange losses	(2)
Purchase of bonds to settle foreign payables	$ 8	$ 30
Investment income (loss)		(8)
Proceeds from sale of bonds		$ 22

Divestitures - Additional Infor

Divestitures - Additional Information (Detail) $ in Millions	9 Months Ended
	Jun. 30, 2023 USD ($)
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Proceeds from sale of business	$ 6

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets - Schedule of Changes in Balances (Detail) $ in Millions	9 Months Ended
	Jun. 30, 2024 USD ($)
Goodwill And Intangible Assets [Line Items]
Beginning balance	$ 134
Foreign currency impact	(2)
Ending balance	132
Reinforcement Materials [Member]
Goodwill And Intangible Assets [Line Items]
Beginning balance	51
Foreign currency impact	(2)
Ending balance	49
Performance Chemicals [Member]
Goodwill And Intangible Assets [Line Items]
Beginning balance	83
Ending balance	$ 83

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets - Schedule of Intangible Assets (Detail) - USD ($) $ in Millions	Jun. 30, 2024	Sep. 30, 2023
Finite Lived Intangible Assets [Line Items]
Gross Carrying Value, finite lives	$ 98	$ 101
Accumulated Amortization	(43)	(41)
Net Intangible Assets, finite lives	55	60
Developed Technologies [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Value, finite lives	33	34
Accumulated Amortization	(11)	(10)
Net Intangible Assets, finite lives	22	24
Trademarks [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Value, finite lives	2	2
Accumulated Amortization	(1)	(1)
Net Intangible Assets, finite lives	1	1
Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Value, finite lives	63	65
Accumulated Amortization	(31)	(30)
Net Intangible Assets, finite lives	$ 32	$ 35

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Goodwill And Intangible Assets [Line Items]
Amortization expense estimated for year one	$ 6		$ 6
Amortization expense estimated for year two	6		6
Amortization expense estimated for year three	6		6
Amortization expense estimated for year four	6		6
Amortization expense estimated for year five	6		6
Cost of Sales, Selling and Administrative Expenses and Research and Technical Expenses [Member]
Goodwill And Intangible Assets [Line Items]
Amortization of intangible assets	$ 1	$ 1	$ 4	$ 4
Minimum [Member]
Goodwill And Intangible Assets [Line Items]
Useful life of intangible assets	10 years		10 years
Maximum [Member]
Goodwill And Intangible Assets [Line Items]
Useful life of intangible assets	25 years		25 years
Weighted Average [Member]
Goodwill And Intangible Assets [Line Items]
Useful life of intangible assets	17 years		17 years

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Loss) ("AOCI") - Changes in Each Component of AOCI, Net of Tax (Detail) - USD ($) $ in Millions	3 Months Ended
	Jun. 30, 2024	Mar. 31, 2024	Dec. 31, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	$ 1,507	$ 1,475	$ 1,407	$ 1,232	$ 1,159	$ 1,032
Ending Balance	1,496	1,507	1,475	1,266	1,232	1,159
Currency Translation Adjustment [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	(307)	(296)	(353)	(303)	(348)	(429)
Other comprehensive income (loss) before reclassifications	(66)	(15)	62	(20)	49	88
Amounts reclassified from AOCI			(1)	(1)	(1)	(1)
Less: Other comprehensive income (loss) attributable to noncontrolling interests	(1)	(4)	4	(6)	3	6
Ending Balance	(372)	(307)	(296)	(318)	(303)	(348)
Pension and Other Post-retirement Benefit Liability Adjustments [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	(10)	(9)	(9)	(11)	(10)	(10)
Other comprehensive income (loss) before reclassifications				1
Amounts reclassified from AOCI		(1)		(1)	(1)
Ending Balance	(10)	(10)	(9)	(11)	(11)	(10)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	(317)	(305)	(362)	(314)	(358)	(439)
Other comprehensive income (loss) before reclassifications	(66)	(15)	62	(19)	49	88
Amounts reclassified from AOCI		(1)	(1)	(2)	(2)	(1)
Less: Other comprehensive income (loss) attributable to noncontrolling interests	(1)	(4)	4	(6)	3	6
Ending Balance	$ (382)	$ (317)	$ (305)	$ (329)	$ (314)	$ (358)

Accumulated Other Comprehensi_4

Accumulated Other Comprehensive Income (Loss) ("AOCI") - Amounts Reclassified Out of AOCI (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total before tax		$ (2)	$ (3)	$ (5)
(Gains) Losses Reclassified to Interest Expense [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	$ (1)	(1)	(4)	(4)
(Gains) Losses Excluded from Effectiveness Testing and Amortized to Interest Expense [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	$ 1		2	1
Amortization of Actuarial Losses and Prior Service Cost (Credit) [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total before tax		$ (1)	$ (1)	$ (2)

Contingencies - Additional Info

Contingencies - Additional Information (Detail) - USD ($) $ in Millions	Jun. 30, 2024	Sep. 30, 2023
Respirator Liabilities [Member]
Loss Contingencies [Line Items]
Respirator reserve	$ 37	$ 38

Income Tax - Effective Tax Rate

Income Tax - Effective Tax Rate (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Income Tax Disclosure [Abstract]
(Provision) benefit for income taxes	$ (40)	$ (41)	$ (121)	$ (90)
Effective tax rate	25%	32%	31%	28%

Income Tax - Additional Informa

Income Tax - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Income Taxes [Line Items]
Net discrete tax (benefits) expense related to tax settlements	$ (1,000,000)	$ 2,000,000	$ 14,000,000	$ 3,000,000
Uncertain tax positions from expirations of statute of limitations	$ 0	$ 0	$ 1,000,000	$ 1,000,000
United States Internal Revenue Service (IRS) [Member]
Income Taxes [Line Items]
Tax years remain subject to examination			2021 2022 2023
State Tax Authorities [Member]
Income Taxes [Line Items]
Tax years remain subject to examination			2018 2019 2020 2021 2022 2023
Foreign Jurisdictions [Member]
Income Taxes [Line Items]
Tax years remain subject to examination			2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023

Earnings Per Share - Components

Earnings Per Share - Components of Basic and Diluted Earnings (Loss) Per Common Share (EPS) (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Basic EPS:
Net income (loss) attributable to Cabot Corporation	$ 109	$ 82	$ 243	$ 211
Less: Dividends and dividend equivalents to participating securities				1
Less: Undistributed earnings allocated to participating securities	1	1	3	3
Earnings (loss) allocated to common stockholders (numerator)	$ 108	$ 81	$ 240	$ 207
Weighted average common shares and participating securities outstanding	55.9	57.3	56.2	57.5
Less: Participating securities	0.8	1.2	0.9	1.3
Adjusted weighted average common shares (denominator)	55.1	56.1	55.3	56.2
Earnings (loss) per common share - basic:	$ 1.96	$ 1.44	$ 4.34	$ 3.68
Diluted EPS:
Earnings (loss) allocated to common stockholders	$ 108	$ 81	$ 240	$ 207
Plus: Earnings allocated to participating securities	1	1	3	4
Less: Adjusted earnings allocated to participating securities	1	1	3	4
Earnings (loss) allocated to common stockholders (numerator)	$ 108	$ 81	$ 240	$ 207
Adjusted weighted average common shares outstanding	55.1	56.1	55.3	56.2
Common shares issuable	0.6	0.4	0.5	0.5
Adjusted weighted average common shares (denominator)	55.7	56.5	55.8	56.7
Earnings (loss) per common share - diluted:	$ 1.94	$ 1.43	$ 4.3	$ 3.65

Earnings Per Share - Calculatio

Earnings Per Share - Calculation of Undistributed Earnings (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Earnings Per Share [Abstract]
Net income (loss) attributable to Cabot Corporation	$ 109	$ 82	$ 243	$ 211
Less: Dividends declared on common stock	24	23	69	64
Less: Dividends declared on participating securities				1
Undistributed earnings (loss)	85	59	174	146
Undistributed earnings (loss) allocated to common shareholders	84	58	171	143
Undistributed earnings allocated to participating shareholders	$ 1	$ 1	$ 3	$ 3

Earnings Per Share - Componen_2

Earnings Per Share - Components of Basic and Diluted Earnings (Loss) Per Common Share (EPS) (Parenthetical) (Detail) - shares	3 Months Ended		9 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Earnings Per Share [Abstract]
Antidilutive securities excluded from computation of earnings per share	0	156,550	209,478	133,039

Restructuring - Additional Info

Restructuring - Additional Information (Details) - RM Plan and PC Plan [Member] - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Jun. 30, 2024	Jun. 30, 2024
Restructuring Cost and Reserve [Line Items]
Severance related costs and accelerated depreciation	$ 1	$ 13
Expected additional restructuring charges		$ 1

Restructuring - Recorded Restru

Restructuring - Recorded Restructuring Activities (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Jun. 30, 2024	Mar. 31, 2024	Dec. 31, 2023	Jun. 30, 2024
Restructuring Cost and Reserve [Line Items]
Total	$ 1	$ 3	$ 9	$ 13
Cost of Sales [Member]
Restructuring Cost and Reserve [Line Items]
Total	1			12
Selling and Administrative Expenses [Member]
Restructuring Cost and Reserve [Line Items]
Total	$ 0			$ 1

Restructuring - Restructuring A

Restructuring - Restructuring Activities and Related Reserves (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Jun. 30, 2024	Mar. 31, 2024	Dec. 31, 2023	Jun. 30, 2024
Restructuring Cost and Reserve [Line Items]
Reserve balance	$ 4	$ 2	$ 0	$ 0
Charges	1	3	9	13
Costs charged against assets			(6)
Cash paid	(3)	(1)	(1)
Reserve balance	2	4	2	2
Severance and Employee Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Reserve balance	3	2	0	0
Charges		2	3
Cash paid	(2)	(1)	(1)
Reserve balance	1	3	2	1
Accelerated Depreciation on Assets [Member]
Restructuring Cost and Reserve [Line Items]
Reserve balance			0	0
Charges, Accelerated depreciation on assets			6
Costs charged against assets			$ (6)
Other [Member]
Restructuring Cost and Reserve [Line Items]
Reserve balance	1
Charges	1	1
Cash paid	(1)
Reserve balance	$ 1	$ 1		$ 1

Financial Instruments and Fai_2

Financial Instruments and Fair Value Measurements - Additional Information (Detail) - USD ($)	9 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Sep. 30, 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, liabilities, Level 2 to Level 1 transfers, amount	$ 0	$ 0
Fair value, assets, Level 2 to Level 1 transfers, amount	0	0
Fair value, liabilities, Level 1 to Level 2 transfers, amount	0	0
Fair value, assets, Level 1 to Level 2 transfers, amount	0	0
Fair value, assets, transfers into Level 3, amount	0	0
Fair value, assets, transfers out of Level 3, amount	0	0
Fair value, liabilities, transfers into Level 3, amount	0	0
Fair value, liabilities, transfers out of Level 3, amount	0	$ 0
Fixed Rate Debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying value of long-term debt	1,070,000,000		$ 1,080,000,000
Fair value of long-term debt	1,040,000,000		1,040,000,000
Foreign Currency Risks [Member] | Prepaid Expenses and Other Current Assets Accounts Payable and Accrued Liabilities and Other Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets (liabilities), at fair Value	9,000,000		12,000,000
Significant Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets in the Consolidated Balance Sheets	$ 8,000,000		$ 8,000,000

Supplier Financing Programs - A

Supplier Financing Programs - Additional Information (Details) - USD ($) $ in Millions	Jun. 30, 2024	Sep. 30, 2023
Supplier Finance Program [Line Items]
Outstanding payment obligations to financial institutions related to supplier financing programs	$ 17	$ 17
Supplier Finance Program, Obligation, Current, Statement of Financial Position [Extensible Enumeration]	Accounts Payable and Accrued Liabilities, Current	Accounts Payable and Accrued Liabilities, Current

Financial Information by Segm_3

Financial Information by Segment - Additional Information (Detail)	9 Months Ended
	Jun. 30, 2024 Segment
Segment Reporting Information [Line Items]
Number of business reportable segments	2

Financial Information by Segm_4

Financial Information by Segment - Financial Information by Reportable Segment (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Segment Reporting Information [Line Items]
Revenues from external customers	$ 1,016	$ 968	$ 2,993	$ 2,966
Income (loss) before income taxes	158	130	394	324
Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues from external customers	981	931	2,894	2,858
Income (loss) before income taxes	191	164	534	437
Unallocated and Other [Member]
Segment Reporting Information [Line Items]
Revenues from external customers	35	37	99	108
Income (loss) before income taxes	(33)	(34)	(140)	(113)
Reinforcement Materials [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues from external customers	649	624	1,966	1,939
Income (loss) before income taxes	136	132	414	348
Performance Chemicals [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues from external customers	332	307	928	919
Income (loss) before income taxes	$ 55	$ 32	$ 120	$ 89

Financial Information by Segm_5

Financial Information by Segment - Revenues From External Customers That are Categorized as Unallocated and Other Reflects Royalties, External Shipping and Handling Fees, The Impact of Unearned Revenue, Discounting Charges For Certain Notes Receivable, and Other By-product Revenue (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Segment Reporting Information [Line Items]
Revenues from external customers	$ 1,016	$ 968	$ 2,993	$ 2,966
Unallocated and Other [Member]
Segment Reporting Information [Line Items]
Revenues from external customers	35	37	99	108
Unallocated and Other [Member] | Shipping and Handling Costs [Member]
Segment Reporting Information [Line Items]
Revenues from external customers	31	31	93	100
Unallocated and Other [Member] | Other [Member]
Segment Reporting Information [Line Items]
Revenues from external customers	$ 4	$ 6	$ 6	$ 8

Financial Information by Segm_6

Financial Information by Segment - Schedule of Income (Loss) from Continuing Operations before Income Taxes and Equity in Earnings of Affiliated Companies for Unallocated and Other (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Segment Reporting Information [Line Items]
Interest expense	$ (19)	$ (24)	$ (62)	$ (69)
Gain on sale of land				1
Loss on sale of business				(3)
Unallocated and Other [Member]
Segment Reporting Information [Line Items]
Interest expense	(19)	(24)	(62)	(69)
Unallocated corporate costs	(16)	(11)	(51)	(42)
General unallocated income (expense)	6	3	34	9
Less: Equity in earnings of affiliated companies, net of tax	2	1	5	4
Income from continuing operations before income taxes and equity in earnings of affiliated companies	(33)	(34)	(140)	(113)
Certain Items [Member]
Segment Reporting Information [Line Items]
Global restructuring activities (Note H)	(1)		(13)
Acquisition and integration-related charges		(1)		(2)
Legal and environmental matters and reserves			(1)	(2)
Gain on sale of land				1
Loss on sale of business				(3)
Other	1		1	(1)
Total certain items	(2)	$ (1)	(56)	$ (7)
Certain Items [Member] | Argentina [Member]
Segment Reporting Information [Line Items]
Controlled currency devaluation and other losses	$ (2)		$ (43)

Financial Information by Segm_7

Financial Information by Segment - Revenue from External Customers by Geographic Region (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Segment Reporting Information [Line Items]
Net sales and other operating revenues	$ 1,016	$ 968	$ 2,993	$ 2,966
Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales and other operating revenues	981	931	2,894	2,858
Unallocated and Other [Member]
Segment Reporting Information [Line Items]
Net sales and other operating revenues	35	37	99	108
Americas [Member]
Segment Reporting Information [Line Items]
Net sales and other operating revenues	368	354	1,077	1,064
Asia Pacific [Member]
Segment Reporting Information [Line Items]
Net sales and other operating revenues	377	353	1,132	1,120
Europe, Middle East and Africa [Member]
Segment Reporting Information [Line Items]
Net sales and other operating revenues	236	224	685	674
Reinforcement Materials [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales and other operating revenues	649	624	1,966	1,939
Reinforcement Materials [Member] | Americas [Member]
Segment Reporting Information [Line Items]
Net sales and other operating revenues	265	260	793	781
Reinforcement Materials [Member] | Asia Pacific [Member]
Segment Reporting Information [Line Items]
Net sales and other operating revenues	245	234	760	752
Reinforcement Materials [Member] | Europe, Middle East and Africa [Member]
Segment Reporting Information [Line Items]
Net sales and other operating revenues	139	130	413	406
Performance Chemicals [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales and other operating revenues	332	307	928	919
Performance Chemicals [Member] | Americas [Member]
Segment Reporting Information [Line Items]
Net sales and other operating revenues	103	94	284	283
Performance Chemicals [Member] | Asia Pacific [Member]
Segment Reporting Information [Line Items]
Net sales and other operating revenues	132	119	372	368
Performance Chemicals [Member] | Europe, Middle East and Africa [Member]
Segment Reporting Information [Line Items]
Net sales and other operating revenues	$ 97	$ 94	$ 272	$ 268

Subsequent Event - Additional I

Subsequent Event - Additional Information (Details) $ in Millions	Jul. 19, 2024 USD ($)
Subsequent Event [Member] | Asset Purchase Agreement [Member]
Subsequent Event [Line Items]
Purchase price of assets	$ 27