Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net earnings attributable to BorgWarner Inc.		$ 184.9	$ 83.3	$ 586.1	$ 411.8
Other comprehensive income (loss)
Foreign currency translation adjustments		64.2	27.9	186.6	41.8
Hedge instruments	[1]	(1.7)	(2.3)	(5.2)	1.1
Defined benefit postretirement plans	[1]	(1.8)	(2.9)	(6.2)	(2.5)
Other	[1]	0.0	0.1	1.2	(1.2)
Total other comprehensive income attributable to BorgWarner Inc.		60.7	22.8	176.4	39.2
Comprehensive income attributable to BorgWarner Inc.		245.6	106.1	762.5	451.0
Comprehensive income attributable to the noncontrolling interest		1.1	2.2	4.5	2.3
Comprehensive income		$ 246.7	$ 108.3	$ 767.0	$ 453.3

[1] Net of income taxes.