Stock Options and Employee Stock Purchase Plan (Details 2) (USD $)				12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2012 Range I [Member]	Sep. 30, 2012 Range II [Member]	Sep. 30, 2012 Range III [Member]	Sep. 30, 2012 Range IV [Member]
Options outstanding segregated by range
Exercise Price, Lower range				$ 4.20	$ 10.10	$ 15.00	$ 21.40
Exercise Price, Upper range				$ 9.90	$ 14.83	$ 19.40	$ 46.90
Option Outstanding at September 30, 2012	846,280	785,547	764,718	478,370	200,801	121,801	45,308
Option Outstanding, Weighted Average Remaining Contractual Life				7 years 6 months	5 years 6 months	5 years 7 months 6 days	4 years 2 months 12 days
Outstanding Options, Weighted Average Exercise Price	$ 11.28	$ 11.52	$ 10.98	$ 7.53	$ 13.04	$ 15.89	$ 33.63
Options Exercisable at September 30, 2012	555,135	535,668		263,179	146,533	100,115	45,308
Options Exercisable, Weighted Average Exercise Price				$ 6.41	$ 12.92	$ 16.04	$ 33.63