Inventory - Additional Information (Details) - USD ($) $ in Thousands |
Mar. 31, 2019 |
Dec. 31, 2018 |
|||
---|---|---|---|---|---|
Inventory [Line Items] | |||||
Prepayment made for manufacturing services | $ 8,249 | $ 7,906 | [1] | ||
Contract Manufacturing Organization | |||||
Inventory [Line Items] | |||||
Prepayment made for manufacturing services | $ 7,300 | $ 6,600 | |||
|