RESTRUCTURING - Schedule of Reserve by Type of Cost (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Restructuring Cost and Reserve [Line Items]
Restructuring expense			$ 23	$ 15
Restructuring expense	$ 17	$ 25	48	44
Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring expense	0	1	1	1
Turbos & Thermal Technologies
Restructuring Cost and Reserve [Line Items]
Restructuring expense	10	8	17	15
Drivetrain & Morse Systems
Restructuring Cost and Reserve [Line Items]
Restructuring expense	1	1	2	10
PowerDrive Systems
Restructuring Cost and Reserve [Line Items]
Restructuring expense	1	14	17	17
Battery & Charging Systems
Restructuring Cost and Reserve [Line Items]
Restructuring expense	5	1	11	1
Employee termination benefits
Restructuring Cost and Reserve [Line Items]
Restructuring expense	13	17	33	30
Employee termination benefits \| Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring expense	0	1	1	1
Employee termination benefits \| Turbos & Thermal Technologies
Restructuring Cost and Reserve [Line Items]
Restructuring expense	8	4	13	9
Employee termination benefits \| Drivetrain & Morse Systems
Restructuring Cost and Reserve [Line Items]
Restructuring expense	1	1	1	9
Employee termination benefits \| PowerDrive Systems
Restructuring Cost and Reserve [Line Items]
Restructuring expense	1	10	9	10
Employee termination benefits \| Battery & Charging Systems
Restructuring Cost and Reserve [Line Items]
Restructuring expense	3	1	9	1
Other
Restructuring Cost and Reserve [Line Items]
Restructuring expense	4	8	15	14
Other \| Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring expense	0	0	0	0
Other \| Turbos & Thermal Technologies
Restructuring Cost and Reserve [Line Items]
Restructuring expense	2	4	4	6
Other \| Drivetrain & Morse Systems
Restructuring Cost and Reserve [Line Items]
Restructuring expense	0	0	1	1
Other \| PowerDrive Systems
Restructuring Cost and Reserve [Line Items]
Restructuring expense	0	4	8	7
Other \| Battery & Charging Systems
Restructuring Cost and Reserve [Line Items]
Restructuring expense	$ 2	$ 0	$ 2	$ 0

BORGWARNER INC 10-Q