REPORTABLE SEGMENTS AND RELATED INFORMATION - Earnings before interest and income taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Segment Reporting Information
Segment Adjusted Operating Income	$ 537	$ 410	$ 991	$ 862
Corporate, including stock-based compensation	63	62	121	125
Merger, acquisition and divestiture expense, net	56		86
Intangible asset amortization expense	24	27	48	50
Restructuring expense	12	27	19	42
Service and lease agreement termination	9	0	9	0
Gain on sale of business	(5)	0	(5)	(24)
Gain on sale of asset	(6)	0	(6)	0
Other non-comparable items	1	13	(4)	13
Equity in affiliates’ earnings, net of tax	(14)	(11)	(18)	(19)
Unrealized loss (gain) on debt and equity securities	54	(11)	69	28
Interest expense, net	12	15	22	30
Other postretirement expense (income)	3	(9)	5	(18)
Earnings before income taxes and noncontrolling interest	328	288	645	603
Provision for income taxes	106	57	193	148
Net earnings	222	231	452	455
Net earnings attributable to noncontrolling interest, net of tax	18	15	31	39
Net earnings attributable to BorgWarner Inc.	204	216	421	416
Air Management
Segment Reporting Information
Segment Adjusted Operating Income	307	244	592	495
Drivetrain & Battery Systems
Segment Reporting Information
Segment Adjusted Operating Income	140	113	250	226
Restructuring expense		2		9
Fuel Systems
Segment Reporting Information
Segment Adjusted Operating Income	57	44	105	110
Aftermarket
Segment Reporting Information
Segment Adjusted Operating Income	52	51	97	90
ePropulsion
Segment Reporting Information
Segment Adjusted Operating Income	$ (19)	$ (42)	$ (53)	$ (59)