Restructuring (Tables)

12 Months Ended

Sep. 30, 2018

Restructuring And Related Activities [Abstract]

Recorded Restructuring Activities

Cabot’s restructuring activities were recorded in the Consolidated Statements of Operations as follows:

	Years Ended September 30
	2018			2017		2016
	(In millions)
Cost of sales	$	(31	)	$	2	$	33
Selling and administrative expenses		1			1		9
Research and development expenses		—			—		5
Total	$	(30	)	$	3	$	47

Restructuring Activities and Related Reserves

Details of all restructuring activities and the related reserves for fiscal 2016, 2017, and 2018 were as follows:

	Severance and Employee Benefits			Environmental Remediation and Decommissioning Activities			Non-Cash Asset Impairment and Accelerated Depreciation			Asset Sales			Other			Total
	(In millions)
Reserve at September 30, 2015	$	5		$	2		$	—		$	—		$	2		$	9
Charges (gain)		28			—			23			(9	)		5			47
Costs charged against assets		—			—			(23	)		(7	)		—			(30	)
Cash (paid) received		(30	)		—			—			16			(7	)		(21	)
Foreign currency translation adjustment		—			—			—			—			—			—
Reserve at September 30, 2016		3			2			—			—			—			5
Charges (gain)		1			1			—			—			1			3
Costs charged against liabilities		—			—			—			—			1			1
Cash paid		(3	)		(1	)		—			—			(2	)		(6	)
Foreign currency translation adjustment		—			—			—			—			—			—
Reserve at September 30, 2017		1			2			—			—			—			3
Charges (gain)		2			3			1			(38	)		2			(30	)
Costs charged against assets		—			—			(1	)		(1	)		—			(2	)
Cash (paid) received		(2	)		(1	)		—			39			(2	)		34
Foreign currency translation adjustment		—			—			—			—			—			—
Reserve at September 30, 2018	$	1		$	4		$	—		$	—		$	—		$	5