Commitments and Contingencies (Schedule of Other Long-Term Commitments) (Detail) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012
Long-term Purchase Commitment [Line Items]
Payments Due by Fiscal Year 2013	$ 452
Payments Due by Fiscal Year 2014	318
Payments Due by Fiscal Year 2015	297
Payments Due by Fiscal Year 2016	235
Payments Due by Fiscal Year 2017	208
Payments Due Thereafter	2,888
Payments Due, Total	4,398
Reinforcement Materials [Member]
Long-term Purchase Commitment [Line Items]
Payments Due by Fiscal Year 2013	386
Payments Due by Fiscal Year 2014	270
Payments Due by Fiscal Year 2015	255
Payments Due by Fiscal Year 2016	195
Payments Due by Fiscal Year 2017	171
Payments Due Thereafter	2,609
Payments Due, Total	3,886
Performance Materials [Member]
Long-term Purchase Commitment [Line Items]
Payments Due by Fiscal Year 2013	40
Payments Due by Fiscal Year 2014	33
Payments Due by Fiscal Year 2015	33
Payments Due by Fiscal Year 2016	32
Payments Due by Fiscal Year 2017	29
Payments Due Thereafter	256
Payments Due, Total	423
Purification Solutions [Member]
Long-term Purchase Commitment [Line Items]
Payments Due by Fiscal Year 2013	21
Payments Due by Fiscal Year 2014	12
Payments Due by Fiscal Year 2015	8
Payments Due by Fiscal Year 2016	8
Payments Due by Fiscal Year 2017	8
Payments Due Thereafter	23
Payments Due, Total	80
Advanced Technologies [Member]
Long-term Purchase Commitment [Line Items]
Payments Due by Fiscal Year 2013	5
Payments Due by Fiscal Year 2014	3
Payments Due by Fiscal Year 2015	1
Payments Due by Fiscal Year 2016
Payments Due by Fiscal Year 2017
Payments Due Thereafter
Payments Due, Total	$ 9