Income Taxes: (Details) (USD $)	12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
Current provision (benefit):
Federal	$ 46,792	$ 183,527	$ (33,770)
State	(9,476)	(518)	(64,243)
Total current provision (benefit)	37,316	183,009	(98,013)
Deferred (benefit) provision:
Federal	(2,435,049)
State	670	751	(11,081)
Total deferred (benefit) provision	(2,434,379)	751	(11,081)
Total current and deferred (benefit) provision	$ (2,397,063)	$ 183,760	$ (109,094)
Reconciliation of the statutory federal rate to the Company's effective income tax rate
U.S. Federal statutory tax rate (as a percent)	34.00%	34.00%	34.00%
State income taxes, net of federal benefit (as a percent)	6.50%	(7.10%)	13.80%
Permanent items (as a percent)	(1.80%)	(0.40%)	1.30%
Research and development tax credits (as a percent)	(3.60%)	(27.50%)	(20.70%)
Valuation allowance (as a percent)	(433.50%)	14.20%	(38.70%)
Change in unrecognized tax benefits (as a percent)	(13.50%)	7.20%	(6.80%)
Effective income tax rate (as a percent)	(411.90%)	20.40%	(17.10%)