Intangible Assets - Schedule of Intangible Assets (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended	12 Months Ended
	Mar. 31, 2014	Sep. 30, 2013
Intangible Assets [Line Items]
Definite lived intangible assets, Weighted Average Original Life (Years)	0 years
Definite lived intangible assets, Gross Carrying Amount	$ 8,223	$ 8,223
Definite lived intangible assets, Accumulated Amortization	(4,906)	(4,535)
Definite lived intangible assets, Net	3,317	3,688
Customer Lists [Member]
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	(3,543)	(3,274)
Definite lived intangible assets, Net	1,314	1,583
Core Technology [Member]
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	(442)	(409)
Definite lived intangible assets, Net	88	121
Patents and Other [Member]
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	(921)	(852)
Definite lived intangible assets, Net	1,335	1,404
Definite-lived intangible assets [Member]
Intangible Assets [Line Items]
Definite lived intangible assets, Weighted Average Original Life (Years)	0 years
Definite lived intangible assets, Gross Carrying Amount	7,643	7,643
Definite lived intangible assets, Accumulated Amortization	(4,906)	(4,535)
Definite lived intangible assets, Net	2,737	3,108
Trademarks [Member]
Intangible Assets [Line Items]
Definite lived intangible assets, Weighted Average Original Life (Years)	0 years
Definite lived intangible assets, Gross Carrying Amount	580	580
Definite lived intangible assets, Accumulated Amortization
Definite lived intangible assets, Net	$ 580	$ 580