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

Stock Based Compensation - Company utilized Black-Scholes pricing model (Details)

v3.21.2
Stock Based Compensation - Company utilized Black-Scholes pricing model (Details) - Evolv Technologies Holdings, Inc.
$ in Thousands
 3 Months Ended 6 Months Ended 12 Months Ended
Jun. 30, 2021
USD ($)
Vote
shares
Jun. 30, 2020
USD ($)
Jun. 30, 2021
USD ($)
Vote
shares
Jun. 30, 2020
USD ($)
Dec. 31, 2020
USD ($)
Dec. 31, 2019
USD ($)
Jan. 31, 2021
USD ($)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]              
Common stock warrant liability | $ $ 922   $ 922   $ 1   $ 19,600
Shares issuable upon exercise of warrant | shares 348,598   348,598        
Aggregate intrinsic value of warrants exercisable | $ $ 1,000   $ 1,000        
Number of warrants unvested | shares 6,408,055   6,408,055        
Intrinsic value of warrants unvested | $ $ 18,500   $ 18,500        
Stock compensation expense | $ $ 535 $ 60 $ 1,617 $ 122 $ 662 $ 264  
Risk-free interest rate              
Fair Value Measurement Inputs and Valuation Techniques [Line Items]              
Measurement input | Vote 0.4   0.4        
Expected term (in years)              
Fair Value Measurement Inputs and Valuation Techniques [Line Items]              
Measurement input | Vote 3.0   3.0        
Expected volatility              
Fair Value Measurement Inputs and Valuation Techniques [Line Items]              
Measurement input | Vote 23.9   23.9        
Expected dividend yield              
Fair Value Measurement Inputs and Valuation Techniques [Line Items]              
Measurement input | Vote 0.0   0.0