Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Basic earnings per share:
Net earnings attributable to BorgWarner Inc.	$ 172	$ 272	$ 332	$ 497
Weighted average shares of common stock outstanding	205.7	208.6	206.1	209.0
Basic earnings per share of common stock	$ 0.84	$ 1.30	$ 1.61	$ 2.38
Diluted earnings per share:
Net earnings attributable to BorgWarner Inc.	$ 172	$ 272	$ 332	$ 497
Weighted average shares of common stock outstanding	205.7	208.6	206.1	209.0
Effect of stock-based compensation	1.1	1.3	0.9	1.3
Weighted average shares of common stock outstanding including dilutive shares	206.8	209.9	207.0	210.3
Diluted earnings per share of common stock	$ 0.83	$ 1.30	$ 1.60	$ 2.36
Awards Granted in 2018 [Member] | Performance Shares [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Antidilutive securities excluded from computation of earnings per share amount	0.0	0.1	0.0	0.2