Financial Instruments - Cash and Cash Equivalents Held in Investment Portfolio (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 14,145,901	$ 24,987,603
Gross Unrealized Gains	0	0
Gross Unrealized (Losses)	0	0
Fair Value	14,145,901	24,987,603
Cash [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	2,655,834	1,398,928
Gross Unrealized Gains	0	0
Gross Unrealized (Losses)	0	0
Fair Value	2,655,834	1,398,928
Cash equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	11,490,067	23,588,675
Gross Unrealized Gains	0	0
Gross Unrealized (Losses)	0	0
Fair Value	$ 11,490,067	$ 23,588,675

Amount of accumulated pre-tax unrealized gain before deducting pre-tax unrealized losses on investments in available-for-sale securities impacting investments.

No definition available.

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- Definition

Amount of accumulated pre-tax unrealized loss before deducting pre-tax unrealized gain on investments in available-for-sale securities impacting investments.

+ References

No definition available.

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- Definition

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)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

This item represents the aggregate fair value of investments in debt and equity securities in an unrealized loss position which are categorized neither as held-to-maturity nor trading securities.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 6

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27290-111563

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