Investments - Summary of Investments by Type of Security (Detail) (USD $)	Mar. 31, 2015	Sep. 30, 2014
Schedule Of Available For Sale Securities [Line Items]
Cost	$ 22,496,666	$ 18,348,998
Gross Unrealized Gains	1,850	1,472
Gross Unrealized Losses	(15,514)	(9,282)
Fair Market Value	22,483,002us-gaap_InvestmentsFairValueDisclosure	18,341,188us-gaap_InvestmentsFairValueDisclosure
Corporate debt securities [Member] \| Short-term [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost	19,979,906	16,273,996
Gross Unrealized Gains	998	1,472
Gross Unrealized Losses	(15,514)	(6,298)
Fair Market Value	19,965,390	16,269,170
Corporate debt securities [Member] \| Long-term [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost	2,516,760	2,075,002
Gross Unrealized Gains	852
Gross Unrealized Losses		(2,984)
Fair Market Value	$ 2,517,612	$ 2,072,018

Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27161-111563

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Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)

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This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.2)

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Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Available-for-Sale Securities

-URI http://asc.fasb.org/extlink&oid=6505594

Reference 2: http://www.xbrl.org/2003/role/presentationRef

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-Name Accounting Standards Codification

-Glossary Trading Securities

-URI http://asc.fasb.org/extlink&oid=6526789

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 1

-Subparagraph a, f, g

-Article 7

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