Organization and Significant Accounting Policies - Additional Information (Detail) - USD ($)	6 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Sep. 30, 2015	Sep. 30, 2014
Schedule Of Investments [Line Items]
Cash and cash equivalents	$ 50,300,847	$ 96,447,301	$ 81,214,354	$ 132,510,610
Investments	11,160,442		17,539,902
Net increase (decrease) in cash	(30,913,507)	(36,063,309)
Cash outflow related to continuing operating activities	(35,895,904)	(40,569,584)
Proceeds from sale of marketable securities	6,200,000	$ 12,150,774
Restricted Cash	0		$ 0
Amount insured in FDIC per account	$ 250,000
Minimum
Schedule Of Investments [Line Items]
Property, Plant and Equipment, Useful Life	3 years
Maximum
Schedule Of Investments [Line Items]
Property, Plant and Equipment, Useful Life	7 years
Commercial bonds
Schedule Of Investments [Line Items]
Maturity description	less than 12 months