CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares
Jun. 30, 2020
Dec. 31, 2019
Common stock    
Common stock, par value (in dollars per share) $ 0.0001 $ 0.0001
Common stock, shares authorized 100,000,000 100,000,000
Common stock, shares issued 21,834,692 21,746,392
Common stock, shares outstanding 21,834,692 21,746,392
Class A common stock    
Common stock, par value (in dollars per share) $ 0.0001 $ 0.0001
Common stock, shares authorized 3,900,000 3,900,000
Common stock, shares issued 3,819,732 3,819,732
Common stock, shares outstanding 3,819,732 3,819,732