General form of registration statement for all companies including face-amount certificate companies

Summary of Significant Accounting Policies - Stock-based compensation (Details)

v3.21.2
Summary of Significant Accounting Policies - Stock-based compensation (Details) - Evolv Technologies Holdings, Inc. - USD ($)
$ in Thousands
 1 Months Ended 3 Months Ended 6 Months Ended 12 Months Ended
Aug. 31, 2020
Jun. 30, 2021
Jun. 30, 2020
Jun. 30, 2021
Jun. 30, 2020
Dec. 31, 2020
Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Granted       17,130,123   24,558,325  
Stock compensation expense   $ 535 $ 60 $ 1,617 $ 122 $ 662 $ 264
Business development agreement term       3 years      
Options to purchase common stock              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Granted       6,756,653      
Stock compensation expense   $ 264 $ 60 $ 467 $ 122 $ 100  
Options to purchase common stock | Officer              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Granted 1,481,982         1,481,982  
Stock compensation expense           $ 100