v3.26.1
Net Income Per Share - Schedule of Reconciliations of the Numerators and Denominators Used to Compute Basic and Diluted (Details) - USD ($)
$ / shares in Units, $ in Thousands
 3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Earnings Per Share [Abstract]    
Net income attributable to Black Rock Coffee Bar, Inc. $ 378 $ 0
Weighted-average number of shares of Class A common stock outstanding (in shares) 17,562,299  
Basic net income per share attributable to Class A common shareholders (in dollars per share) $ 0.02  
Diluted net income attributable to Black Rock Coffee Bar, Inc. $ 378  
Weighted-average number of shares of Class A common stock outstanding used to calculate diluted net income per share (in shares) 17,562,299  
Diluted net income per share attributable to Class A common shareholders (in dollars per share) $ 0.02