Intangible Assets (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Sep. 30, 2012
Intangible Assets [Line Items]
Intangible assets, Gross carrying amount	$ 8,223	$ 8,223
Intangible assets, Accumulated amortization	(4,163)	(3,793)
Intangible assets, Net	4,060	4,430
Customer Lists
Intangible Assets [Line Items]
Definite lived intangible assets, Weighted Average Original Life (Years)	9 years	9 years
Definite lived intangible assets, Gross Carrying Amount	4,857	4,857
Definite lived intangible assets, Accumulated Amortization	(3,004)	(2,734)
Definite lived intangible assets, Net	1,853	2,123
Core Technology
Intangible Assets [Line Items]
Definite lived intangible assets, Weighted Average Original Life (Years)	8 years	8 years
Definite lived intangible assets, Gross Carrying Amount	530	530
Definite lived intangible assets, Accumulated Amortization	(375)	(343)
Definite lived intangible assets, Net	155	187
Patents And Other
Intangible Assets [Line Items]
Definite lived intangible assets, Weighted Average Original Life (Years)	16 years 9 months 18 days	16 years 9 months 18 days
Definite lived intangible assets, Gross Carrying Amount	2,256	2,256
Definite lived intangible assets, Accumulated Amortization	(784)	(716)
Definite lived intangible assets, Net	1,472	1,540
Subtotal
Intangible Assets [Line Items]
Definite lived intangible assets, Gross Carrying Amount	7,643	7,643
Definite lived intangible assets, Accumulated Amortization	(4,163)	(3,793)
Definite lived intangible assets, Net	3,480	3,850
Trademarks
Intangible Assets [Line Items]
Unamortized intangible assets, Gross	580	580
Unamortized intangible assets, Net	$ 580	$ 580