Organization and Description of Business - Additional Information (Detail) - Follow-on Offering [Member] - USD ($) $ / shares in Units, $ in Millions |
Aug. 03, 2018 |
Jul. 25, 2017 |
Jul. 27, 2016 |
|---|---|---|---|
| Organization And Description Of Business [Line Items] | |||
| Number of shares issued | 5,750,000 | 32,000,000 | 14,000,000 |
| Public offering price, per unit | $ 2.00 | ||
| Net proceeds received | $ 10.4 | $ 37.1 | $ 32.0 |
| X | ||||||||||
- Definition Organization And Description Of Business [Line Items] No definition available.
|
| X | ||||||||||
- Definition Cash received on stock transaction after deduction of issuance costs. No definition available.
|
| X | ||||||||||
- Definition Per share or per unit amount of equity securities issued. No definition available.
|
| X | ||||||||||
- Definition Number of new stock issued during the period. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Details
|