Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Basic earnings per share:
Net earnings attributable to BorgWarner Inc.	$ 160	$ 225
Weighted average shares of common stock outstanding	206.5	209.5
Basic earnings per share of common stock	$ 0.77	$ 1.07
Diluted earnings per share:
Net earnings attributable to BorgWarner Inc.	$ 160	$ 225
Weighted average shares of common stock outstanding	206.5	209.5
Effect of stock-based compensation	0.6	1.3
Weighted average shares of common stock outstanding including dilutive shares	207.1	210.8
Diluted earnings per share of common stock	$ 0.77	$ 1.07
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	0.5	0.0