Investments - Summary of Investments by Type of Security (Detail) - USD ($)	Dec. 31, 2015	Sep. 30, 2015
Schedule Of Available For Sale Securities [Line Items]
Cost	$ 23,273,171	$ 23,924,252
Gross Unrealized Gains	257	3,466
Gross Unrealized Losses	(23,468)	(6,390)
Fair Market Value	23,249,960	23,921,328
Corporate debt securities [Member] \| Short-term [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost	19,570,392	23,924,252
Gross Unrealized Gains		3,466
Gross Unrealized Losses	(16,520)	(6,390)
Fair Market Value	19,553,872	$ 23,921,328
Corporate debt securities [Member] \| Long-term [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost	751,610
Gross Unrealized Losses	(3,860)
Fair Market Value	747,750
Government debt securities [Member] \| Short-term [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost	1,551,424
Gross Unrealized Gains	257
Gross Unrealized Losses	(158)
Fair Market Value	1,551,523
Government debt securities [Member] \| Long-term [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost	1,399,745
Gross Unrealized Losses	(2,930)
Fair Market Value	$ 1,396,815

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 25
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=51813488&loc=d3e22054-111558

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section 50
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

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-Publisher FASB
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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.

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