Net Loss Per Share - Computation of Net Loss Per Share (Details) - USD ($)
$ / shares in Units, $ in Thousands
3 Months Ended 6 Months Ended 12 Months Ended
Jun. 30, 2021
Mar. 31, 2021
Jun. 30, 2020
Mar. 31, 2020
Jun. 30, 2021
Jun. 30, 2020
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Numerator:                  
Net loss - Basic and Diluted $ (79,595)   $ (20,157)   $ (133,187) $ (35,679)      
Denominator:                  
Weighted average common shares outstanding - Basic and Diluted (in shares) 385,945,332   289,823,175   371,519,800 284,054,689 294,549,146 261,228,108 236,040,717
Net loss per share attributable to common stockholders - Basic and Diluted (in dollars per share) $ (0.21)   $ (0.07)   $ (0.36) $ (0.13) $ (0.49) $ (0.09) $ (0.12)
Numerator:                  
Net loss $ (79,595) $ (53,592) $ (20,157) $ (15,522) $ (133,187) $ (35,679) $ (145,510) $ (23,605) $ (27,780)