Condensed Consolidated Statements of Comprehensive Income (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Net earnings attributable to BorgWarner Inc.	$ 120.6	$ 162.0	$ 278.6	$ 286.5
Foreign currency translation adjustments	(90.7)	40.1	(45.9)	131.3
Market value change of hedge instruments	(0.5)	(10.8)	13.7	(15.3)
Income taxes associated with the market value change of hedge instruments	0.8	3.7	(4.3)	4.4
Hedge instrument adjustments - (Gain) loss reclassified into net earnings	1.9	0.6	2.6	0.8
Hedge instruments adjustments - Income taxes reclassified into net earnings	(0.8)	(0.3)	(1.0)	(0.5)
Net change in hedge instruments	1.4	(6.8)	11.0	(10.6)
Defined benefit post employment plans - Net unrecognized loss arising during the period	(0.7)	0	(0.7)	0
Defined benefit post employment plans - Income taxes associated with net unrecognized loss arising during the period	0.3	0	0.3	0
Defined benefit post employment plans - Amortization of prior service benefit and unrecognized loss into net earnings	2.2	1.8	4.4	3.8
Defined benefit post employment plans - Income taxes reclassified into net earnings	(0.8)	(0.7)	(1.4)	(1.3)
Defined benefit post employment plans - Acquisition	0	0	0	(5.4)
Defined benefit post employment plans - Income taxes associated with acquisition	0	0	0	1.4
Net change in defined benefit post employment plans	(1.0)	(1.1)	(2.6)	1.5
Other changes in OCI, net of tax	0.5	0.2	0.5	0.2
Comprehensive income	32.8	196.6	246.8	405.9
Comprehensive income (loss) attributable to noncontrolling interest	(0.8)	1.3	0.1	2.7
Comprehensive income attributable to BorgWarner Inc.	$ 32.0	$ 197.9	$ 246.9	$ 408.6