v3.26.1
Stock-Based Compensation - Non-Plan Co-Founder and Head of Blend Options (Details) - USD ($)
$ / shares in Units, $ in Thousands
1 Months Ended 3 Months Ended 6 Months Ended 12 Months Ended
Mar. 31, 2021
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Dec. 31, 2025
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Stock based compensation expense   $ 6,978 $ 7,582 $ 13,758 $ 13,678  
Unrecognized compensation expense   400   $ 400    
Stock Options            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Unrecognized compensation expense, period of recognition (in years)       6 months    
Non-employee | Stock Options            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Option forfeitures in period (in shares)           5,862,866
Stock based compensation expense   600 $ 900 $ 1,100 $ 2,300  
Unrecognized compensation expense   $ 3,700   $ 3,700    
Unrecognized compensation expense, period of recognition (in years)       2 years 2 months 12 days    
Non-employee | Class B Common Stock            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Granted (in shares) 26,057,181          
Granted (in dollars per share) $ 8.58          
Non-employee | Class B Common Stock | Tranche One            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Expected to vest (in shares) 1,954,289          
Non-employee | Class B Common Stock | Stock Options            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Vesting period (in years) 15 years          
Performance period (in months) 15 months