Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity - Equity Incentive Plans (Details)

v3.20.2
Stockholders' Equity - Equity Incentive Plans (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Dec. 15, 2016
Jun. 30, 2020
Jun. 30, 2019
Jun. 30, 2020
Jun. 30, 2019
Equity Incentive Plans          
Stock-based compensation   $ 767 $ 793 $ 1,658 $ 1,547
Research and Development Expense          
Equity Incentive Plans          
Stock-based compensation   204 192 413 424
General and Administrative Expense          
Equity Incentive Plans          
Stock-based compensation   $ 563 $ 601 $ 1,245 $ 1,123
Maximum          
Equity Incentive Plans          
Term of award       10 years  
Vesting period       4 years  
2008 Plan and 2013 Plan          
Equity Incentive Plans          
Authorized (in shares) 500,000