Accumulated Other Comprehensive Income Loss Attributable To Non Controlling Interest

No definition available.

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- Definition

Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 11

-URI http://asc.fasb.org/extlink&oid=36458714&loc=d3e637-108580

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 14

-URI http://asc.fasb.org/extlink&oid=36458714&loc=d3e681-108580

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 14A

-URI http://asc.fasb.org/extlink&oid=36458714&loc=SL7669686-108580

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 31

-Article 5

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

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- Definition

Amount after tax, before reclassification adjustments of other comprehensive income (loss).

+ References

No definition available.

+ Details

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- Definition

Amount after tax and reclassification adjustments of other comprehensive income (loss).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 1A

-URI http://asc.fasb.org/extlink&oid=36458714&loc=SL7669619-108580

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- Definition

Amount after tax of reclassification adjustments of other comprehensive income (loss).

+ References

No definition available.

+ Details

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Accumulated Other Comprehensive Loss - Changes in Each Component of AOCI, Net of Tax (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended			6 Months Ended
	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014	Mar. 31, 2015	Mar. 31, 2014	Sep. 30, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance attributable to Cabot Corporation	$ (144)	$ (64)		$ (64)
Other comprehensive loss before reclassifications	(131)	(103)
Amounts reclassified from accumulated other comprehensive income	1	21
Net other comprehensive items	(130)	(82)	(7)	(212)	(28)
Less: Noncontrolling interest	(1)	(2)		(1)
Balance attributable to Cabot Corporation	(273)	(144)		(273)
Currency Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance attributable to Cabot Corporation	(74)	27		27
Other comprehensive loss before reclassifications	(131)	(103)
Net other comprehensive items	(131)	(103)
Less: Noncontrolling interest	(1)	(2)		(1)
Balance attributable to Cabot Corporation	(204)	(74)		(204)
Unrealized Gains on Investments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance attributable to Cabot Corporation						2
Balance attributable to Cabot Corporation	2	2		2		2
Pension and Other Postretirement Benefit Liability Adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance attributable to Cabot Corporation	(72)	(93)		(93)
Amounts reclassified from accumulated other comprehensive income	1	21
Net other comprehensive items	1	21
Balance attributable to Cabot Corporation	$ (71)	$ (72)		$ (71)