Organization and Description of Business - Additional Information (Detail) - USD ($) |
3 Months Ended | ||||
|---|---|---|---|---|---|
Nov. 02, 2015 |
Jun. 12, 2015 |
Mar. 31, 2016 |
Mar. 31, 2015 |
Dec. 31, 2015 |
|
| Organization And Description Of Business [Line Items] | |||||
| Additional stock reserved for future issuance | 18,214,615 | 17,816,862 | |||
| Proceeds from exercise of warrants | $ 0 | $ 400 | |||
| Private Placement [Member] | |||||
| Organization And Description Of Business [Line Items] | |||||
| Number of securities received by investors | 4,728,128 | ||||
| Additional stock reserved for future issuance | 2,364,066 | ||||
| Warrant exercise price per share | $ 8.00 | $ 4.65 | |||
| Net proceeds received | $ 18,300,000 | ||||
| Warrants expiration date | Jun. 11, 2020 | ||||
| Class B Warrants [Member] | |||||
| Organization And Description Of Business [Line Items] | |||||
| Warrants exercised | 4,812,328 | ||||
| Common stock shares issued upon exercise of warrants | 2,406,164 | ||||
| Proceeds from exercise of warrants | $ 9,600,000 | ||||
| Unexercised warrants terminated | 2,068,005 | ||||
| Warrants expiration date | Nov. 02, 2015 | ||||