CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Millions, $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Statement [Abstract]
Net sales		$ 10,165	$ 10,168	$ 10,530
Cost of sales		8,255	8,067	8,300
Gross profit		1,910	2,101	2,230
Selling, general and administrative expenses		951	873	946
Other operating expense (income), net		341	(75)	94
Operating income		618	1,303	1,190
Equity in affiliates’ earnings, net of tax		(18)	(32)	(49)
Unrealized gain on equity securities		(382)	0	0
Interest income		(12)	(12)	(6)
Interest expense		73	55	59
Other postretirement (income) expense		(7)	27	(10)
Earnings before income taxes and noncontrolling interest		964	1,265	1,196
Provision for income taxes		397	468	211
Net earnings		567	797	985
Net earnings attributable to the noncontrolling interest, net of tax	[1]	67	51	54
Net earnings attributable to BorgWarner Inc.		$ 500	$ 746	$ 931
Earnings Per Share
Basic (in dollars per share)		$ 2.35	$ 3.63	$ 4.47
Diluted (in dollars per share)		$ 2.34	$ 3.61	$ 4.44
Weighted average shares outstanding:
Basic (shares)		213.0	205.7	208.2
Diluted (shares)		214.0	206.8	209.5

[1] Net of income taxes.