Warrants - Summary of Warrants Outstanding (Detail) - $ / shares |
3 Months Ended | ||
|---|---|---|---|
Mar. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
|
| Class of Warrant or Right [Line Items] | |||
| Warrants Outstanding | 2,177,425 | 2,177,425 | 17,559 |
| Class One [Member] | |||
| Class of Warrant or Right [Line Items] | |||
| Exercise Price | $ 3.10 | ||
| Warrants Outstanding | 48,387 | ||
| Expiration Date | Sep. 19, 2022 | ||
| Class Two [Member] | |||
| Class of Warrant or Right [Line Items] | |||
| Exercise Price | $ 3.10 | ||
| Warrants Outstanding | 462,106 | ||
| Expiration Date | May 10, 2024 | ||
| Class Three [Member] | |||
| Class of Warrant or Right [Line Items] | |||
| Exercise Price | $ 3.10 | ||
| Warrants Outstanding | 602,414 | ||
| Expiration Date | Jul. 25, 2024 | ||
| Class Four [Member] | |||
| Class of Warrant or Right [Line Items] | |||
| Exercise Price | $ 3.10 | ||
| Warrants Outstanding | 1,064,518 | ||
| Expiration Date | Nov. 08, 2024 |