v3.26.1
Restructuring expenses (Details) - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Restructuring Cost and Reserve [Line Items]    
Restructuring expenses $ 2 $ 51
Severance costs   36
Non-cash branch and facility costs   15
Corporate restructuring expenses    
Restructuring Cost and Reserve [Line Items]    
Restructuring expenses 2 0
Business restructuring expenses    
Restructuring Cost and Reserve [Line Items]    
Restructuring expenses $ 0 $ 51