Summary of Significant Accounting Policies - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Schedule Of Significant Accounting Policies [Line Items]
Sales value of inventory	$ 9,517	$ 19,346
Carrying value of floating-rate term loan	55,500
Fair value of floating-rate term loan	55,898
Percentage of tax benefits recognized upon settlement	50.00%
Machinery and Equipment | Minimum
Schedule Of Significant Accounting Policies [Line Items]
Estimated productive lives of the assets	3 years
Machinery and Equipment | Maximum
Schedule Of Significant Accounting Policies [Line Items]
Estimated productive lives of the assets	15 years
Building Improvements | Minimum
Schedule Of Significant Accounting Policies [Line Items]
Estimated productive lives of the assets	7 years
Building Improvements | Maximum
Schedule Of Significant Accounting Policies [Line Items]
Estimated productive lives of the assets	30 years
Leasehold Improvements | Minimum
Schedule Of Significant Accounting Policies [Line Items]
Estimated productive lives of the assets	7 years
Leasehold Improvements | Maximum
Schedule Of Significant Accounting Policies [Line Items]
Estimated productive lives of the assets	9 years
Accounts Receivable | Fine Chemicals Customer One
Schedule Of Significant Accounting Policies [Line Items]
Concentration risk from customers having more than 10% of accounts receivable	14.00%	27.00%
Accounts Receivable | Fine Chemicals Customer Two
Schedule Of Significant Accounting Policies [Line Items]
Concentration risk from customers having more than 10% of accounts receivable	12.00%	16.00%
Accounts Receivable | Fine Chemicals Customer Three
Schedule Of Significant Accounting Policies [Line Items]
Concentration risk from customers having more than 10% of accounts receivable	10.00%
Accounts Receivable | Specialty Chemicals Customer
Schedule Of Significant Accounting Policies [Line Items]
Concentration risk from customers having more than 10% of accounts receivable	15.00%	19.00%
Interest Rate Swap
Schedule Of Significant Accounting Policies [Line Items]
Fair value of the swap agreement	256
Related Party Transactions
Schedule Of Significant Accounting Policies [Line Items]
Total transactions	$ 120	$ 180	$ 146