v3.26.3
Description of business (Details)
$ / shares in Units, $ in Thousands
 1 Months Ended 3 Months Ended 9 Months Ended
Sep. 17, 2026
USD ($)
$ / shares
shares
Jun. 06, 2025
USD ($)
$ / shares
shares
Aug. 31, 2025
USD ($)
$ / shares
shares
Jun. 30, 2025
USD ($)
$ / shares
shares
Sep. 30, 2026
USD ($)
$ / shares
shares
Sep. 30, 2025
USD ($)
Sep. 30, 2026
USD ($)
class
$ / shares
shares
Sep. 30, 2025
USD ($)
Dec. 31, 2025
$ / shares
shares
Collaborative Arrangement and Arrangement Other than Collaborative                  
Net of issuance costs | $             $ 365 $ 0  
Preferred stock, shares authorized (in shares)   500,000,000.0              
Number of classes of common stock | class             3    
Share-based payment arrangement, expense | $   $ 423,800              
Capitalized stock-based compensation expense related to internally developed software | $   $ 62,700     $ 10,600 $ 9,200 $ 33,800 $ 77,600  
Share-based compensation arrangement by share-based payment award, accelerated vesting, number (in shares)   9,500,000              
Shares withheld for tax withholding requirements (in shares)   4,000,000.0              
Class A common stock                  
Collaborative Arrangement and Arrangement Other than Collaborative                  
Common stock, shares authorized (in shares)   2,500,000,000     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   $ 0.0001
Preferred stock par value (in dollars per share) | $ / shares   $ 0.0001              
Common stock, shares, issued (in shares)         237,100,000   237,100,000   223,600,000
Conversion of stock, shares issued (in shares)   139,800,000              
Class A common stock | IPO                  
Collaborative Arrangement and Arrangement Other than Collaborative                  
Number of shares issued (in shares)       19,900,000          
Purchase price per share (in dollars per share) | $ / shares       $ 31.00          
Sale of stock, consideration received on transaction | $       $ 583,000          
Net of issuance costs | $       $ 12,800          
Class A common stock | Private Placement                  
Collaborative Arrangement and Arrangement Other than Collaborative                  
Number of shares issued (in shares) 1,200,000     19,200,000          
Purchase price per share (in dollars per share) | $ / shares $ 80.84                
Sale of stock, consideration received on transaction | $ $ 100,000     $ 0          
Class A common stock | Follow-on Public Offering                  
Collaborative Arrangement and Arrangement Other than Collaborative                  
Number of shares issued (in shares)     3,500,000            
Purchase price per share (in dollars per share) | $ / shares     $ 130.00            
Sale of stock, consideration received on transaction | $     $ 444,800            
Net of issuance costs | $     $ 1,800            
Class A common stock | Follow-on Public Offering | Selling Stockholders                  
Collaborative Arrangement and Arrangement Other than Collaborative                  
Number of shares issued (in shares)     8,000,000.0            
Sale of stock, consideration received on transaction | $     $ 0            
Class B common stock                  
Collaborative Arrangement and Arrangement Other than Collaborative                  
Common stock, shares authorized (in shares)   500,000,000.0     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   $ 0.0001
Common stock, shares, issued (in shares)         19,100,000   19,100,000   19,100,000
Class B common stock | Co-Founder                  
Collaborative Arrangement and Arrangement Other than Collaborative                  
Conversion of stock, shares issued (in shares)   19,600,000              
Class C common stock                  
Collaborative Arrangement and Arrangement Other than Collaborative                  
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   $ 0.0001
Common stock, shares, issued (in shares)   500,000,000.0     0   0   0