Significant Accounting Policies - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Jun. 30, 2014 Customer	Sep. 30, 2013
Significant Accounting Policies [Line Items]
Revenue recognized due	2022
Number of customer having licensing agreements	1
Goodwill	$ 555	$ 502
Value of inventories under FIFO method	53	55
Purification Solutions [Member]
Significant Accounting Policies [Line Items]
Goodwill	$ 468	$ 466
Approximate percentage of fair value of reporting unit exceeds carrying value	9.00%
Successful realization of anticipated market share, years	3 years
Buildings [Member] | Minimum [Member]
Significant Accounting Policies [Line Items]
Useful life of property, plant and equipment	20 years
Buildings [Member] | Maximum [Member]
Significant Accounting Policies [Line Items]
Useful life of property, plant and equipment	25 years
Machinery and Equipment [Member] | Minimum [Member]
Significant Accounting Policies [Line Items]
Useful life of property, plant and equipment	10 years
Machinery and Equipment [Member] | Maximum [Member]
Significant Accounting Policies [Line Items]
Useful life of property, plant and equipment	25 years
Other Fixed Assets [Member] | Minimum [Member]
Significant Accounting Policies [Line Items]
Useful life of property, plant and equipment	3 years
Other Fixed Assets [Member] | Maximum [Member]
Significant Accounting Policies [Line Items]
Useful life of property, plant and equipment	25 years