Basis of Presentation - Additional Information (Detail) - USD ($)	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Revenues	$ 0
Net loss	2,119,397	$ 1,982,696
Cash used in operations	1,366,650	$ 1,900,495
Accumulated deficit	$ 103,578,864		$ 101,400,797

Amount of cash inflow (outflow) from operating activities, including discontinued operations. Operating activity cash flows include transactions, adjustments, and changes in value not defined as investing or financing activities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 24
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3521-108585

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 942
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-Subparagraph (SX 210.9-04(22))
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The cumulative amount of the reporting entity's undistributed earnings or deficit.

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Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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