v3.26.1
STOCKHOLDERS' EQUITY AND NET LOSS PER SHARE - Narrative (Details)
$ / shares in Units, shares in Thousands, $ in Millions
 3 Months Ended 6 Months Ended
Jul. 07, 2026
USD ($)
$ / shares
shares
Jun. 30, 2026
shares
Jun. 30, 2026
USD ($)
shares
Jun. 30, 2025
USD ($)
Dec. 31, 2025
shares
Class of Stock [Line Items]          
Common stock, shares outstanding (in shares)   1,362,000 1,362,000   1,240,000
Common stock, shares issued (in shares)   1,362,000 1,362,000   1,240,000
Common stock, shares authorized (in shares)   5,258,000 5,258,000   5,258,000
Conversion ratio   1 1    
Anniversary period one (in years)     5 years    
Anniversary period two (in months)     6 months    
Proceeds from issuance of capital stock | $     $ 1,300 $ 750  
Subsequent Event | Private Placement          
Class of Stock [Line Items]          
Number of shares issued in transaction (in shares) 75,000        
Price per share (in dollars per share) | $ / shares $ 15.50        
Proceeds from issuance of capital stock | $ $ 1,317        
Subsequent Event | Over-Allotment Option          
Class of Stock [Line Items]          
Number of shares issued in transaction (in shares) 11,250        
Chief Executive Officer          
Class of Stock [Line Items]          
Shares owned (as percent)   30.00% 30.00%    
Common Class A          
Class of Stock [Line Items]          
Common stock, shares outstanding (in shares)   1,358,000 1,358,000   1,236,000
Common stock, shares issued (in shares)   1,358,000 1,358,000   1,236,000
Common stock, shares authorized (in shares)   5,250,000 5,250,000   5,250,000
Common Class A | Volkswagen Group | Testing Milestone Payments | Related Party          
Class of Stock [Line Items]          
Number of shares issued in transaction (in shares)   63,000      
Common Class B          
Class of Stock [Line Items]          
Common stock, shares outstanding (in shares)   4,000 4,000   4,000
Common stock, shares issued (in shares)   4,000 4,000   4,000
Common stock, shares authorized (in shares)   8,000 8,000   8,000