Significant Accounting Policies - Segment Reporting Revenue Percentage (Detail)	3 Months Ended		9 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Reinforcement Materials [Member]
Segment Reporting Information [Line Items]
Revenue, by segment	59.00%	56.00%	58.00%	57.00%
Performance Materials [Member]
Segment Reporting Information [Line Items]
Revenue, by segment	27.00%	27.00%	27.00%	27.00%
Purification Solutions [Member]
Segment Reporting Information [Line Items]
Revenue, by segment	9.00%	9.00%	9.00%	10.00%
Advanced Technologies [Member]
Segment Reporting Information [Line Items]
Revenue, by segment	5.00%	8.00%	6.00%	6.00%