Earnings Per Share (Details) (USD $) In Millions, except Share data in Thousands, unless otherwise specified	3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013 Call Option [Member]	Sep. 30, 2012 Call Option [Member]	Sep. 30, 2013 Call Option [Member]	Sep. 30, 2012 Call Option [Member]	Mar. 31, 2012 Senior Notes One [Member]
Basic earnings per share:
Net earnings attributable to BorgWarner Inc.	$ 166.8	$ 101.1	$ 482.9	$ 379.7
Weighted average shares of common stock outstanding	113,819	114,299	114,584	111,619
Earnings per share — basic	$ 1.47	$ 0.88	$ 4.21	$ 3.40
Diluted earnings per share:
Net earnings attributable to BorgWarner Inc.	166.8	101.1	482.9	379.7
Adjustment for net interest expense on convertible notes	0	0	0	5.8
Diluted net earnings attributable to BorgWarner Inc.	$ 166.8	$ 101.1	$ 482.9	$ 385.5
Weighted average shares of common stock outstanding	113,819	114,299	114,584	111,619
Effect of 3.50% convertible notes	0	0	0	4,429
Effect of warrant	0	2,208	0	4,507
Effect of stock-based compensation	1,419	1,992	1,384	2,016
Total dilutive effect on weighted average shares of common stock outstanding	1,419	4,200	1,384	10,952
Weighted average shares of common stock outstanding including dilutive shares	115,238	118,499	115,968	122,571
Earnings per share — diluted	$ 1.45	$ 0.85	$ 4.16	$ 3.15
Anti-dilutive securities					0	0	0	2,586
Debt Instrument, Interest Rate, Stated Percentage									3.50%
Warrant Exercise Price				$ 38.61
Bond Hedge Per Share Price				$ 32.82