Investments - Summary of Fair Value of Investments Measured on Recurring Basis (Detail) (USD $)	Sep. 30, 2014	Sep. 30, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of investments measured on recurring basis, total	$ 18,341,188	$ 5,730,872
Short-term Investments [Member] | Recurring [Member] | Level-2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of investments measured on recurring basis, total	16,269,170	5,730,872
Short-term Investments [Member] | Recurring [Member] | Level-2 [Member] | Commercial paper [Member] | Financial [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of investments measured on recurring basis, total	2,198,043
Short-term Investments [Member] | Recurring [Member] | Level-2 [Member] | Commercial paper [Member] | Industrial [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of investments measured on recurring basis, total		399,900
Short-term Investments [Member] | Recurring [Member] | Level-2 [Member] | Corporate debt securities [Member] | Financial [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of investments measured on recurring basis, total	9,334,140	3,411,661
Short-term Investments [Member] | Recurring [Member] | Level-2 [Member] | Corporate debt securities [Member] | Industrial [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of investments measured on recurring basis, total	3,980,772	1,517,327
Short-term Investments [Member] | Recurring [Member] | Level-2 [Member] | Corporate debt securities [Member] | Utility [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of investments measured on recurring basis, total	756,215	401,984
Long-term Investments [Member] | Recurring [Member] | Level-2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of investments measured on recurring basis, total	2,072,018
Long-term Investments [Member] | Recurring [Member] | Level-2 [Member] | Financial [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of investments measured on recurring basis, total	1,564,505
Long-term Investments [Member] | Recurring [Member] | Level-2 [Member] | Utility [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of investments measured on recurring basis, total	$ 507,513