Accumulated Other Comprehensive Income (Loss)

12 Months Ended

Sep. 30, 2024

Stockholders' Equity Note [Abstract]

Accumulated Other Comprehensive Income (Loss)

Note P. Accumulated Other Comprehensive Income (Loss)

Changes in each component of AOCI, net of tax, are as follows for fiscal 2024 and 2023:

	Currency Translation Adjustment			Pension and Other Postretirement Benefit Liability Adjustment			Total
	(In millions)
Balance at September 30, 2022 attributable to    Cabot Corporation	$	(429	)	$	(10	)	$	(439	)
Other comprehensive income (loss) before reclassifications		80			3			83
Amounts reclassified from AOCI		(4	)		(2	)		(6	)
Less: Other comprehensive income (loss) attributable to    noncontrolling interests		—			—			—
Balance at September 30, 2023 attributable to    Cabot Corporation		(353	)		(9	)		(362	)
Other comprehensive income (loss) before reclassifications		18			(5	)		13
Amounts reclassified from AOCI		(2	)		(4	)		(6	)
Less: Other comprehensive income (loss) attributable to    noncontrolling interests		5			—			5
Balance at September 30, 2024 attributable to    Cabot Corporation	$	(342	)	$	(18	)	$	(360	)

The amounts reclassified out of AOCI and into the Consolidated Statements of Operations for fiscal 2024, 2023 and 2022 are as follows:

	Affected Line Item in the Consolidated	Years Ended September 30
	Statements of Operations	2024			2023			2022
		(In Millions)
Derivatives: net investment hedges
(Gains) losses reclassified to interest    expense	Interest expense	$	(5	)	$	(6	)	$	(6	)
(Gains) losses excluded from effectiveness    testing and amortized to interest expense	Interest expense		2			2			2
Release of current translation adjustment	Loss on sale of business and asset impairment charge		—			—			33
Pension and other postretirement benefit    liability adjustment
Release of actuarial losses and prior service cost    (credits)	Loss on sale of business and asset impairment charge		—			—			2
Amortization of actuarial losses and prior service    cost (credit)	Other income (expense)		(2	)		(2	)		1
Settlement and curtailment loss (gain)	Other income (expense)		—			—			(1	)
Total before tax		$	(5	)	$	(6	)	$	31