Financial Information about Segment Operations (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting Information [Line Items]
Revenues	$ 36,318	$ 38,485
Corporate Expenses	(4,086)	(3,626)
Operating Income (Loss)	4,948	2,759
Depreciation and amortization	3,310	3,373
Fine Chemicals
Segment Reporting Information [Line Items]
Revenues	21,347	21,475
Operating Income (Loss)	1,277	(1,187)
Depreciation and amortization	3,015	3,040
Specialty Chemicals
Segment Reporting Information [Line Items]
Revenues	14,350	14,220
Operating Income (Loss)	7,917	7,644
Depreciation and amortization	207	235
Other Businesses
Segment Reporting Information [Line Items]
Revenues	621	2,790
Operating Income (Loss)	(160)	(72)
Depreciation and amortization	5	4
Total Operating Segments
Segment Reporting Information [Line Items]
Operating Income (Loss)	9,034	6,385
Corporate
Segment Reporting Information [Line Items]
Depreciation and amortization	$ 83	$ 94