Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Basic earnings per share:
Net earnings attributable to BorgWarner Inc.	$ 83.3	$ 157.4	$ 411.8	$ 484.4
Weighted average shares of common stock outstanding	212,872	224,837	215,332	225,329
Basic earnings per share of common stock	$ 0.39	$ 0.70	$ 1.91	$ 2.15
Diluted earnings per share:
Net earnings attributable to BorgWarner Inc.	$ 83.3	$ 157.4	$ 411.8	$ 484.4
Weighted average shares of common stock outstanding	212,872	224,837	215,332	225,329
Effect of stock-based compensation	894	1,154	857	1,236
Weighted average shares of common stock outstanding including dilutive shares	213,766	225,991	216,189	226,565
Diluted earnings per share of common stock	$ 0.39	$ 0.70	$ 1.90	$ 2.14