Financial Information by Segment - Schedule of Performance Segment (Detail) (Performance Materials [Member], Operating Segments [Member], USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended
Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013
Segment Reporting Information [Line Items]
Net sales	$ 249	$ 243	$ 466	$ 439
Specialty Carbons and Compounds [Member]
Segment Reporting Information [Line Items]
Net sales	172	173	320	305
Fumed Metal Oxides [Member]
Segment Reporting Information [Line Items]
Net sales	$ 77	$ 70	$ 146	$ 134

Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 1

-Article 5

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration