Condensed Consolidated Statements of Comprehensive Income (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Statement of Comprehensive Income [Abstract]
Net earnings attributable to BorgWarner Inc.	$ 166.8	$ 101.1	$ 482.9	$ 379.7
Foreign currency translation adjustments
Foreign currency translation adjustments	94.5	64.2	4.7	18.3
Hedge instrument adjustments
Market value change of hedge instruments			12.1
Income taxes associated with the market value change of hedge instruments			8.5
Loss (gain) reclassified into net earnings			8.7
Income taxes reclassified into net earnings			(1.7)
Hedge instruments	0.4	(3.7)	14.0	7.3
Defined benefit postretirement plans
Defined benefit postretirement plans	1.9	1.5	11.1	4.1
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax, Portion Attributable to Parent			0.5	0.5
Total other comprehensive income attributable to BorgWarner Inc.	96.8	62.0	30.3	30.2
Comprehensive income attributable to BorgWarner Inc.	266.3	164.4	513.6	411.3
Comprehensive income attributable to the noncontrolling interest	2.7	1.3	0.4	1.4
Comprehensive income	$ 263.6	$ 163.1	$ 513.2	$ 409.9