Earnings Per Share (Details) (USD $) In Millions, except Share data in Thousands, unless otherwise specified	3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013 Call Option [Member]	Jun. 30, 2012 Call Option [Member]	Jun. 30, 2013 Call Option [Member]	Jun. 30, 2012 Call Option [Member]	Mar. 31, 2012 Senior Notes One [Member]
Basic earnings per share:
Net earnings attributable to BorgWarner Inc.	$ 174.1	$ 120.6	$ 316.1	$ 278.6
Weighted average shares of common stock outstanding	114,748	112,139	114,967	110,280
Earnings per share — basic	$ 1.52	$ 1.08	$ 2.75	$ 2.53
Diluted earnings per share:
Net earnings attributable to BorgWarner Inc.	174.1	120.6	316.1	278.6
Adjustment for net interest expense on convertible notes	0	0.8	0	5.8
Diluted net earnings attributable to BorgWarner Inc.	$ 174.1	$ 121.4	$ 316.1	$ 284.4
Weighted average shares of common stock outstanding	114,748	112,139	114,967	110,280
Effect of 3.50% convertible notes	0	1,898	0	6,644
Effect of warrant	0	5,499	0	5,656
Effect of stock-based compensation	1,353	1,937	1,366	2,028
Total dilutive effect on weighted average shares of common stock outstanding	1,353	9,334	1,366	14,328
Weighted average shares of common stock outstanding including dilutive shares	116,101	121,473	116,333	124,608
Earnings per share — diluted	$ 1.50	$ 1.00	$ 2.72	$ 2.28
Anti-dilutive securities					0	1,108	0	3,879
Debt Instrument, Interest Rate, Stated Percentage									3.50%
Warrant Exercise Price				$ 38.61
Bond Hedge Per Share Price				$ 32.82