Summary of Significant Accounting Policies - Additional Information (Detail) |
12 Months Ended | ||
|---|---|---|---|
|
Dec. 31, 2015
USD ($)
Segment
shares
|
Dec. 31, 2014
USD ($)
shares
|
Dec. 31, 2013
USD ($)
|
|
| Schedule Of Significant Accounting Policies [Line Items] | |||
| Lease Expiration Date | Dec. 01, 2020 | Apr. 09, 2015 | |
| Counterparty accounted for all of the Company's revenue and research and license agreement receivable | During 2015, one counterparty accounted for all of the Company's revenue. | ||
| Deferred IPO costs | $ 0 | $ 0 | $ 1,800,000 |
| Long-lived assets, impairment charge | $ 0 | 0 | $ 0 |
| Number of operating segment | Segment | 1 | ||
| Money Market Fund [Member] | |||
| Schedule Of Significant Accounting Policies [Line Items] | |||
| Letter of credit | $ 1,100,000 | ||
| Certificate of Deposit [Member] | |||
| Schedule Of Significant Accounting Policies [Line Items] | |||
| Letter of credit | $ 300,000 | ||
| Preferred Stock [Member] | |||
| Schedule Of Significant Accounting Policies [Line Items] | |||
| Preferred stock warrants outstanding | shares | 0 | 0 | |