Common Stock - Additional Information (Detail) - 2012 Equity Incentive Plan [Member] - Restricted Stock [Member] - USD ($) |
3 Months Ended | 9 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Feb. 09, 2017 |
Feb. 15, 2016 |
Dec. 31, 2017 |
Sep. 30, 2017 |
Jun. 30, 2017 |
Mar. 31, 2017 |
Dec. 31, 2016 |
Sep. 30, 2016 |
Jun. 30, 2016 |
Mar. 31, 2016 |
Sep. 30, 2017 |
|
| Class of Stock [Line Items] | |||||||||||
| Unrecognized compensation expense | $ 8,624 | $ 8,624 | |||||||||
| Non-employee Directors [Member] | |||||||||||
| Class of Stock [Line Items] | |||||||||||
| Restricted shares awarded to each non-employee director | 40,000 | 40,000 | |||||||||
| Restricted shares vest in each quarter end | 10,000 | 10,000 | 10,000 | 10,000 | 10,000 | 10,000 | 10,000 | 30,000 | |||
| Non-employee Directors [Member] | Scenario, Forecast [Member] | |||||||||||
| Class of Stock [Line Items] | |||||||||||
| Restricted shares vest in each quarter end | 10,000 | ||||||||||