v3.26.1
STOCKHOLDERS' EQUITY AND NET LOSS PER SHARE - Narrative (Details)
$ / shares in Units, shares in Millions, $ in Millions
 3 Months Ended
Apr. 30, 2026
USD ($)
$ / shares
shares
Mar. 31, 2026
shares
Dec. 31, 2025
shares
Class of Stock [Line Items]      
Common stock, shares outstanding (in shares)   1,260 1,240
Common stock, shares issued (in shares)   1,260 1,240
Common stock, shares authorized (in shares)   5,258 5,258
Conversion ratio   1  
Anniversary period one (in years)   5 years  
Anniversary period two (in months)   6 months  
Volkswagen Group | Testing Milestone Payments | Subsequent Event | Related Party      
Class of Stock [Line Items]      
Proceeds from stock-based compensation programs | $ $ 1,000    
Chief Executive Officer      
Class of Stock [Line Items]      
Shares owned (as percent)   30.00%  
Common Class A      
Class of Stock [Line Items]      
Common stock, shares outstanding (in shares)   1,256 1,236
Common stock, shares issued (in shares)   1,256 1,236
Common stock, shares authorized (in shares)   5,250 5,250
Common Class A | Volkswagen Group | Testing Milestone Payments | Subsequent Event | Related Party      
Class of Stock [Line Items]      
Number of shares issued in transaction (in shares) 63    
Price per share (in dollars per share) | $ / shares $ 15.90    
Common Class B      
Class of Stock [Line Items]      
Common stock, shares outstanding (in shares)   4 4
Common stock, shares issued (in shares)   4 4
Common stock, shares authorized (in shares)   8 8