Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation - Purchase Plan (Details)

v3.20.2
Stock-Based Compensation - Purchase Plan (Details) - Purchase Plan
9 Months Ended
Sep. 30, 2020
USD ($)
item
shares
Sep. 30, 2019
Jul. 01, 2020
USD ($)
Jan. 02, 2020
USD ($)
Additional disclosures        
Award offering period 24 months      
Number of purchase periods per award offering period | item 4      
Award purchase period 6 months      
Purchase price expressed as a percentage of fair market value of common stock on the purchase date 85.00%      
Purchase price expressed as a percentage of fair market value of common stock on the first day of the offering period 85.00%      
Total incremental fair value for the Purchase Plan reset     $ 535,000 $ 753,000
Shares reserved for future issuance | shares 235,795      
Unrecognized compensation cost related to purchase plan $ 887,000      
Weighted-average assumptions relating to Purchase Plan        
Risk-free interest rate (as a percent) 1.00% 2.80%    
Expected term (in years) 1 year 7 months 6 days 1 year 8 months 12 days    
Dividend yield (as a percent) 0.00% 0.00%    
Expected volatility (as a percent) 62.30% 63.00%