Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Basic earnings per share:
Net earnings attributable to BorgWarner Inc.	$ 189.2	$ 164.1
Weighted average shares of common stock outstanding	211,596	217,388
Basic earnings per share of common stock	$ 0.89	$ 0.75
Diluted earnings per share:
Net earnings attributable to BorgWarner Inc.	$ 189.2	$ 164.1
Weighted average shares of common stock outstanding	211,596	217,388
Effect of stock-based compensation	640	749
Weighted average shares of common stock outstanding including dilutive shares	212,236	218,137
Diluted earnings per share of common stock	$ 0.89	$ 0.75