Short-Term Investments - Summary of Short-term Investments (Details) $ in Thousands |
Dec. 31, 2018
USD ($)
|
|---|---|
| Schedule Of Available For Sale Securities [Line Items] | |
| Amortized Cost | $ 42,163 |
| Gross Unrealized Loss | (17) |
| Fair Value | 42,146 |
| Corporate Bonds and Commercial Paper | |
| Schedule Of Available For Sale Securities [Line Items] | |
| Amortized Cost | 37,168 |
| Gross Unrealized Loss | (17) |
| Fair Value | 37,151 |
| U.S. Government Securities | |
| Schedule Of Available For Sale Securities [Line Items] | |
| Amortized Cost | 4,995 |
| Fair Value | $ 4,995 |