Fair Value Measurements - Schedule of Additional Information about Assets Measured at Fair Value on a Recurring Basis (Detail) - Unobservable Inputs (Level 3) [Member] - USD ($) $ in Thousands |
3 Months Ended | 6 Months Ended |
|---|---|---|
Jun. 30, 2016 |
Jun. 30, 2016 |
|
| Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | ||
| Fair value of Thera Warrant | $ 5 | $ 5 |
| Balance, end of period | $ 5 | $ 5 |