Earnings Per Share (Details) (USD $) In Millions, except Share data in Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Basic earnings per share:
Net earnings attributable to BorgWarner Inc.	$ 166.6	$ 166.8	$ 515.9	$ 482.9
Weighted average shares of common stock outstanding	227,077	227,638	227,395	229,168
Basic earnings per share of common stock	$ 0.73	$ 0.73	$ 2.27	$ 2.11
Diluted earnings per share:
Net earnings attributable to BorgWarner Inc.	$ 166.6	$ 166.8	$ 515.9	$ 482.9
Weighted average shares of common stock outstanding	227,077	227,638	227,395	229,168
Effect of stock-based compensation	1,591	2,838	1,827	2,768
Weighted average shares of common stock outstanding including dilutive shares	228,668	230,476	229,222	231,936
Diluted earnings per share of common stock	$ 0.73	$ 0.72	$ 2.25	$ 2.08