v3.26.1
Stockholders' equity - Common Stock (Details)
 1 Months Ended 6 Months Ended
Jun. 06, 2025
$ / shares
shares
Aug. 31, 2025
$ / shares
shares
Jun. 30, 2025
$ / shares
shares
Jun. 30, 2026
vote
class
$ / shares
shares
Dec. 31, 2025
$ / shares
shares
Class of Stock          
Preferred stock, shares authorized (in shares) 500,000,000.0        
Number of classes of common stock | class       3  
Employee Stock          
Class of Stock          
Common stock reserved for future issuance       8,100,000  
Common Stock Issuable In Connection With Business Combinations          
Class of Stock          
Common stock reserved for future issuance       300,000  
Common Stock Issuable Under Stock Award Plan          
Class of Stock          
Common stock reserved for future issuance       21,800,000  
Shares issued (in shares)       800,000  
Common Stock Available For Future Issuance Under Stock Award Plan          
Class of Stock          
Common stock reserved for future issuance       37,500,000  
Class A common stock          
Class of Stock          
Common stock, shares authorized (in shares) 2,500,000,000     2,500,000,000 2,500,000,000
Common stock, par or stated value per share (in dollars per share) | $ / shares $ 0.0001     $ 0.0001 $ 0.0001
Preferred stock par value (in dollars per share) | $ / shares $ 0.0001        
Common stock, shares, issued (in shares)       233,500,000 223,600,000
Conversion of stock, shares issued 139,800,000        
Number of votes for each share of common stock held | vote       1  
Class A common stock | IPO          
Class of Stock          
Number of shares issued (in shares)     19,900,000    
Purchase price per share (in dollars per share) | $ / shares     $ 31.00    
Class A common stock | Follow-on Public Offering          
Class of Stock          
Number of shares issued (in shares)   3,500,000      
Purchase price per share (in dollars per share) | $ / shares   $ 130.00      
Class B common stock          
Class of Stock          
Common stock, shares authorized (in shares) 500,000,000.0     500,000,000.0 500,000,000.0
Common stock, par or stated value per share (in dollars per share) | $ / shares $ 0.0001     $ 0.0001 $ 0.0001
Common stock, shares, issued (in shares)       19,200,000 19,200,000
Number of votes for each share of common stock held | vote       5  
Common stock aggregate voting power maximum percentage       30.00%  
Class B common stock | Co-Founder          
Class of Stock          
Conversion of stock, shares issued 19,600,000        
Common Class C          
Class of Stock          
Common stock, shares authorized (in shares)       500,000,000.0 500,000,000.0
Common stock, par or stated value per share (in dollars per share) | $ / shares $ 0.0001     $ 0.0001 $ 0.0001
Common stock, shares, issued (in shares) 500,000,000.0     0 0