v3.26.3
Redeemable Convertible Preferred Stock and Shareholders’ Equity - Narrative (Details)
$ / shares in Units, shares in Millions, $ in Millions
 1 Months Ended 3 Months Ended 9 Months Ended
May 31, 2026
Sep. 30, 2026
USD ($)
class
vote
$ / shares
shares
Sep. 30, 2025
USD ($)
shares
Sep. 30, 2026
USD ($)
class
vote
$ / shares
shares
Sep. 30, 2025
USD ($)
shares
Dec. 31, 2025
$ / shares
Class of Stock [Line Items]            
Number of classes of common stock | class   3   3    
Number of classes of preferred stock | class   1   1    
Preferred stock authorized (in shares)   2,400   2,400    
Preferred stock, par value (in USD per share) | $ / shares   $ 0.001   $ 0.001   $ 0.001
Common stock authorized (in shares)   52,257   52,257    
Stock split conversion ratio 5          
Common stock and redeemable convertible preferred stock repurchased | $   $ 0   $ 2,013    
Common stock repurchased (in shares)   0 18   47  
Redeemable convertible preferred stock repurchased (in shares)   0   2    
Common stock repurchased | $     $ 3   $ 523  
Minimum period shares were held by eligible participants before repurchase     6 months   6 months  
Share Repurchases from Existing Shareholders            
Class of Stock [Line Items]            
Common stock repurchased (in shares)       41    
Common stock repurchased | $       $ 1,944    
Share Repurchases from Current and Former xAI Employees            
Class of Stock [Line Items]            
Common stock repurchased (in shares)       25    
Common stock repurchased | $       $ 2,413    
Class A Common Stock            
Class of Stock [Line Items]            
Common stock authorized (in shares)   36,132   36,132    
Common stock, par value (in USD per share) | $ / shares   $ 0.001   $ 0.001   0.001
Number of votes per share of common stock held | vote   1   1    
Class B Common Stock            
Class of Stock [Line Items]            
Common stock authorized (in shares)   6,125   6,125    
Common stock, par value (in USD per share) | $ / shares   $ 0.001   $ 0.001   0.001
Common stock conversion ratio   1   1    
Number of votes per share of common stock held | vote   10   10    
Class C Common Stock            
Class of Stock [Line Items]            
Common stock authorized (in shares)   10,000   10,000    
Common stock, par value (in USD per share) | $ / shares   $ 0.001   $ 0.001   $ 0.001