REPORTING SEGMENTS AND RELATED INFORMATION - Earnings before interest and income taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Segment Reporting Information
Segment Adjusted Operating Income	$ 410	$ 499	$ 862	$ 1,032
Corporate, including stock-based compensation	62	78	125	147
Intangible asset amortization expense	27	20	50	40
Restructuring expense	27	62	42	92
Merger, acquisition and divestiture expense, net	9	15	32	28
Other non-comparable items	13	0	13	(2)
Loss (gain) on sale of business	0	7	(24)	7
Equity in affiliates’ earnings, net of tax	(11)	(16)	(19)	(28)
Unrealized (gain) loss on equity securities	(11)	4	28	276
Interest expense, net	15	39	30	57
Other postretirement income	(9)	(12)	(18)	(23)
Earnings before income taxes and noncontrolling interest	288	302	603	438
Provision for income taxes	57	28	148	70
Net earnings	231	274	455	368
Net earnings attributable to noncontrolling interest, net of tax	15	27	39	56
Net earnings attributable to BorgWarner Inc.	216	247	416	312
Air Management
Segment Reporting Information
Segment Adjusted Operating Income	235	263	478	569
e-Propulsion & Drivetrain
Segment Reporting Information
Segment Adjusted Operating Income	80	132	184	266
Restructuring expense			14
Fuel Systems
Segment Reporting Information
Segment Adjusted Operating Income	44	60	110	117
Aftermarket
Segment Reporting Information
Segment Adjusted Operating Income	$ 51	$ 44	$ 90	$ 80