Subsequent Events - Additional Information (Detail) - USD ($) |
1 Months Ended | |||||
|---|---|---|---|---|---|---|
Jan. 09, 2019 |
Mar. 31, 2019 |
Dec. 31, 2018 |
Jun. 01, 2018 |
Jan. 31, 2018 |
Dec. 31, 2017 |
|
| Subsequent Event [Line Items] | ||||||
| Amount owed by vendor | $ 441,000 | |||||
| Warrants exercisable into shares of common stock | 1,183,116 | 570,287 | ||||
| Exercise price of warrants, per share | $ 3.73 | $ 3.02 | $ 9.15 | |||
| Strike price per share | $ 3.14 | |||||
| Subsequent Events [Member] | Settlement Agreement with Vendor [Member] | ||||||
| Subsequent Event [Line Items] | ||||||
| Amount owed by vendor | $ 164,000 | |||||
| Issuance of restricted common shares | 93,448 | |||||
| Warrants exercisable into shares of common stock | 93,448 | 382,165 | ||||
| Exercise price of warrants, per share | $ 1.64 | |||||
| Strike price per share | $ 3.02 | |||||
| Aggregate proceeds from exercise of warrants | $ 1,154,000 |