Fair Value Considerations - Financial Assets and Liabilities (Detail) - USD ($)	Sep. 30, 2019	Dec. 31, 2018
LIABILITIES
Warrant derivative liability	$ 8,165,955	$ 6,933,031
Fair Value, Inputs, Level 1 [Member]
LIABILITIES
Warrant derivative liability	0	0
Fair Value, Inputs, Level 2 [Member]
LIABILITIES
Warrant derivative liability	0	0
Fair Value, Inputs, Level 3 [Member]
LIABILITIES
Warrant derivative liability	$ 8,166,000	$ 6,933,000

Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled after one year or the normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

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Balance Type:	credit
Period Type:	instant