Acquisitions (Components and Allocation of Purchase Price) (Detail) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Sep. 30, 2012
Business Acquisition [Line Items]
Goodwill	$ 499	$ 480
Norit Nv [Member]
Business Acquisition [Line Items]
Current assets	203	207
Property, plant and equipment	371	385
Other non-current assets	76	72
Intangible assets	317	325
Goodwill	454	432
Current liabilities	(98)	(98)
Deferred non-current tax liabilities	(172)	(176)
Other non-current liabilities	(38)	(34)
Total purchase price	1,113	1,113
Norit Nv [Member] \| Measurement Period Adjustments [Member]
Business Acquisition [Line Items]
Current assets	(4)
Property, plant and equipment	(14)
Other non-current assets	4
Intangible assets	(8)
Goodwill	22
Deferred non-current tax liabilities	4
Other non-current liabilities	$ (4)

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Amount of assets that are expected to be realized or consumed within one year or the normal operating cycle, if longer, acquired at the acquisition date.

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Amount of liabilities due within one year or within the normal operating cycle, if longer, assumed at the acquisition date.

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Amount of deferred tax liability attributable to taxable temporary differences due after one year or the normal operating cycle, if longer, assumed at the acquisition date.

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Amount of intangible assets, excluding goodwill, acquired at the acquisition date.

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Amount of other liabilities due after one year or the normal operating cycle, if longer, assumed at the acquisition date.

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Amount of other assets expected to be realized or consumed after one year or the normal operating cycle, if longer, acquired at the acquisition date.

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The amount of property, plant, and equipment recognized as of the acquisition date.

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

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Amount recognized for assets, including goodwill, in excess of (less than) the aggregate liabilities assumed.

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Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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