Exercise price per share or per unit of warrants or rights outstanding.

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-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
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Number of securities into which the class of warrant or right may be converted. For example, but not limited to, 500,000 warrants may be converted into 1,000,000 shares.

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Number of warrants or rights outstanding.

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Equity Transactions - Warrant Information (Detail) - Common stock purchase warrants - $ / shares	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2015
Vendor
Class Of Warrant Or Right [Line Items]
Number of warrants issued (in shares)	294,117
Warrant exercise price (in USD per share)	$ 1.7
Third Amendment
Class Of Warrant Or Right [Line Items]
Number of warrants issued (in shares)			29,239
Warrant exercise price (in USD per share)			$ 17.1
Loan and Security Agreement
Class Of Warrant Or Right [Line Items]
Number of warrants issued (in shares)		190,140
Warrant exercise price (in USD per share)		$ 2.84
Warrants outstanding (in shares)	169,014