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

Summary of Significant Accounting Policies - Property and equipment (Details)

v3.21.2
Summary of Significant Accounting Policies - Property and equipment (Details)
 6 Months Ended 12 Months Ended
Jun. 30, 2021
Dec. 31, 2020
Property, Plant and Equipment [Line Items]    
Lease term 4 years  
Evolv Technologies Holdings, Inc.    
Property, Plant and Equipment [Line Items]    
Lease term   4 years
Evolv Technologies Holdings, Inc. | Computers and telecommunications equipment    
Property, Plant and Equipment [Line Items]    
Estimated Useful Life 3 years 3 years
Evolv Technologies Holdings, Inc. | Lab equipment    
Property, Plant and Equipment [Line Items]    
Estimated Useful Life 5 years 5 years
Evolv Technologies Holdings, Inc. | Software    
Property, Plant and Equipment [Line Items]    
Estimated Useful Life 4 years 4 years
Evolv Technologies Holdings, Inc. | Furniture and fixtures    
Property, Plant and Equipment [Line Items]    
Estimated Useful Life 5 years 5 years
Evolv Technologies Holdings, Inc. | Leased equipment    
Property, Plant and Equipment [Line Items]    
Estimated Useful Life 7 years 7 years
Lease term 48 months