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

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The number of new shares issued in the conversion of stock in a noncash (or part noncash) transaction. Noncash is defined as transactions during a period that do not result in cash receipts or cash payments in the period. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

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Amount, after accumulated amortization, of debt discount.

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Amount of the cost of borrowed funds accounted for as interest expense for debt.

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The cash outflow for loan origination associated cost which is usually collected through escrow.

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Amount of cash outflow for payment of an obligation from a lender, including but not limited to, letter of credit, standby letter of credit and revolving credit arrangements.

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Fair value portion of warrants not settleable in cash classified as equity.

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Debt - Additional Information (Detail) - USD ($)		1 Months Ended		12 Months Ended
Debt - Additional Information (Detail) - USD ($)	Aug. 04, 2016	Jul. 31, 2016	May 31, 2014	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Repayment of principal and accrued interest					$ 4,500,000
Warrant exercise price per share				$ 3.46	$ 3.29
Loan and Security Agreement [Member]
Debt Instrument [Line Items]
Loan and security agreement, interest incurred				$ 0	$ 148,500
Square 1 Bank [Member] \| Loan and Security Agreement [Member]
Debt Instrument [Line Items]
Repayment of principal and accrued interest	$ 4,500,000
Line of credit facility, loan origination cost			$ 82,685
Debt instrument, unamortized discount	38,000
Warrants exercisable, stock issued					22,881
Warrant exercise price per share					$ 5.90
Square 1 Bank [Member] \| Loan and Security Agreement [Member] \| Warrants to purchase common stock [Member]
Debt Instrument [Line Items]
Debt instrument, unamortized discount	$ 59,000
Common stock shares issued upon conversion of warrants		9,887
Warrant value recorded in equity			$ 108,122