v3.25.2
RESTRUCTURING - Schedule of Restructuring Charges (Details) - Integration 3.0 - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2025
Restructuring Cost and Reserve [Line Items]    
Restructuring charges $ 4 $ 11
Freight Segment    
Restructuring Cost and Reserve [Line Items]    
Restructuring charges 2 3
Transit Segment    
Restructuring Cost and Reserve [Line Items]    
Restructuring charges $ 2 $ 8
Cost of goods sold | Freight Segment    
Restructuring Cost and Reserve [Line Items]    
Restructuring Charges, Statement of Income or Comprehensive Income [Extensible Enumeration] Cost of Product and Service Sold Cost of Product and Service Sold
Restructuring charges $ 1 $ 2
Cost of goods sold | Transit Segment    
Restructuring Cost and Reserve [Line Items]    
Restructuring Charges, Statement of Income or Comprehensive Income [Extensible Enumeration] Cost of Product and Service Sold Cost of Product and Service Sold
Restructuring charges $ 1 $ 3
Selling, general and administrative expenses | Freight Segment    
Restructuring Cost and Reserve [Line Items]    
Restructuring Charges, Statement of Income or Comprehensive Income [Extensible Enumeration] Selling, General and Administrative Expense Selling, General and Administrative Expense
Restructuring charges $ 1 $ 1
Selling, general and administrative expenses | Transit Segment    
Restructuring Cost and Reserve [Line Items]    
Restructuring Charges, Statement of Income or Comprehensive Income [Extensible Enumeration] Selling, General and Administrative Expense Selling, General and Administrative Expense
Restructuring charges $ 1 $ 5