Statements of Comprehensive Loss Parenthetical (Parenthetical) - USD ($) $ in Thousands |
3 Months Ended | |
---|---|---|
Mar. 31, 2019 |
Mar. 31, 2018 |
|
Stock-based compensation expense associated with research and development expense | $ 1,768 | $ 1,655 |
Stock-based compensation expense associated with selling, general and administrative expense | $ 1,643 | $ 1,419 |