Nature of Business - Additional Information (Detail) - USD ($) $ in Thousands |
1 Months Ended | 6 Months Ended | ||
---|---|---|---|---|
Sep. 29, 2016 |
Jan. 31, 2018 |
Jun. 30, 2018 |
Dec. 31, 2017 |
|
Nature Of Business And Basis Of Presentation [Line Items] | ||||
Net proceeds of offering after deducting underwriting discounts and commissions | $ 5,732 | |||
Accumulated deficit | $ 226,797 | $ 208,187 | ||
Private Placement [Member] | ||||
Nature Of Business And Basis Of Presentation [Line Items] | ||||
Proceeds from issuance of common stock, preferred stock and warrants, net of issuance costs | $ 27,600 | |||
Common Stock [Member] | ||||
Nature Of Business And Basis Of Presentation [Line Items] | ||||
Shares issued | 2,691,494 | |||
Net proceeds of offering after deducting underwriting discounts and commissions | $ 5,700 | |||
Common Stock [Member] | Private Placement [Member] | ||||
Nature Of Business And Basis Of Presentation [Line Items] | ||||
Shares issued | 2,596,059 |