Investments - Summary of Short and Long-term Investments (Detail) (USD $)	Sep. 30, 2014	Sep. 30, 2013
Schedule Of Investments [Line Items]
Gross Unrealized Gains		$ 7,500
Gross Unrealized Losses	(407,523)	(41,643)
Fair Value	44,333,855	10,698,271
Commercial notes (due within one year), amortized cost	21,653,032	9,030,261
Commercial notes (due after one year through two years), amortized cost	23,088,346	1,702,153
Total	44,741,378	10,732,414
Commercial Notes Due Within One Year
Schedule Of Investments [Line Items]
Gross Unrealized Gains		7,500
Gross Unrealized Losses	(189,830)	(39,281)
Fair Value	21,463,202	8,998,480
Commercial Notes Due After One Year Through Two Years
Schedule Of Investments [Line Items]
Gross Unrealized Gains
Gross Unrealized Losses	(217,693)	(2,362)
Fair Value	$ 22,870,653	$ 1,699,791