Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) |
1 Months Ended | 12 Months Ended | ||
|---|---|---|---|---|
Sep. 22, 2014 |
Sep. 30, 2014 |
Dec. 31, 2015 |
Dec. 31, 2014 |
|
| Summary Of Significant Accounting Policies [Line Items] | ||||
| Cash equivalents, maturity period | Ninety days or less | |||
| Impairment losses on long-lived assets | $ 0 | |||
| Income tax examination, likelihood of settlement, description | The amount of the benefit that may be recognized is the largest amount that has a greater than 50% likelihood of being realized upon ultimate settlement. | |||
| Income tax examination, likelihood of settlement, percentage | 50.00% | |||
| Deferred tax assets | $ 0 | $ 0 | ||
| Deferred tax liabilities | 0 | |||
| Revenue since inception | 0 | |||
| Total Assets | 67,974,000 | $ 107,744,000 | ||
| Number of common shares issued on conversion of redeemable convertible preferred stock | 14,860,173 | 14,860,173 | ||
| Laboratories [Member] | Non-US [Member] | ||||
| Summary Of Significant Accounting Policies [Line Items] | ||||
| Total Assets | $ 175,000 |