v3.26.1
Revenue - Disaggregated Revenue by Categories (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Disaggregation of Revenue [Line Items]        
Revenues $ 1,566 $ 814 $ 2,972 $ 1,580
Allison Transmission        
Disaggregation of Revenue [Line Items]        
Revenues 860 814 1,593 1,580
Allison Off-Highway        
Disaggregation of Revenue [Line Items]        
Revenues 706 0 1,379 0
North America On-Highway | Allison Transmission        
Disaggregation of Revenue [Line Items]        
Revenues 430 417 805 852
Outside North America On-Highway | Allison Transmission        
Disaggregation of Revenue [Line Items]        
Revenues 132 142 242 254
Global Off-Highway | Allison Transmission        
Disaggregation of Revenue [Line Items]        
Revenues 22 16 30 34
Defense | Allison Transmission        
Disaggregation of Revenue [Line Items]        
Revenues 99 63 186 116
Service Parts, Support Equipment and Other | Allison Transmission        
Disaggregation of Revenue [Line Items]        
Revenues 177 176 330 324
Construction & Material Handling | Allison Off-Highway        
Disaggregation of Revenue [Line Items]        
Revenues 249 0 476 0
Agriculture | Allison Off-Highway        
Disaggregation of Revenue [Line Items]        
Revenues 152 0 306 0
Industrial | Allison Off-Highway        
Disaggregation of Revenue [Line Items]        
Revenues 99 0 189 0
Mining | Allison Off-Highway        
Disaggregation of Revenue [Line Items]        
Revenues 54 0 104 0
Service Parts, Specialty & Other | Allison Off-Highway        
Disaggregation of Revenue [Line Items]        
Revenues $ 152 $ 0 $ 304 $ 0