Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended		12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013	Mar. 31, 2012	Sep. 30, 2012
Intangible Assets
Impairment charges recognized					$ 0
Intangible Assets
Amortization expense of patents, non-competes and other intangibles	103	104	208	216
Total intangible assets, Gross Amount	13,297		13,297		13,887
Finite-lived intangible assets, Accumulated Amortization	(7,488)		(7,488)		(7,870)
Carrying Amount	5,809		5,809		6,017
Patents
Intangible Assets
Finite-lived intangible assets, Gross Amount	8,667		8,667		8,667
Finite-lived intangible assets, Accumulated Amortization	(7,031)		(7,031)		(6,891)
Finite-lived intangible assets, Carrying Amount	1,636		1,636		1,776
Patents | Minimum
Intangible Assets
Useful life			2 years
Patents | Maximum
Intangible Assets
Useful life			14 years
Non-compete
Intangible Assets
Finite-lived intangible assets, Gross Amount	500		500		1,090
Finite-lived intangible assets, Accumulated Amortization	(345)		(345)		(900)
Finite-lived intangible assets, Carrying Amount	155		155		190
Non-compete | Minimum
Intangible Assets
Useful life			2 years
Non-compete | Maximum
Intangible Assets
Useful life			3 years
Other
Intangible Assets
Finite-lived intangible assets, Gross Amount	330		330		330
Finite-lived intangible assets, Accumulated Amortization	(112)		(112)		(79)
Finite-lived intangible assets, Carrying Amount	218		218		251
Trademarks
Intangible Assets
Indefinite-lived intangible assets	$ 3,800		$ 3,800		$ 3,800