BorgWarner Inc. and Consolidated Subsidiaries Statements of Comprehensive Income - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Net earnings attributable to BorgWarner Inc.		$ 439.9	$ 118.5	$ 609.7
Foreign currency translation adjustments		236.5	(109.1)	(260.5)
Hedge instruments	[1]	(6.3)	7.0	(3.7)
Defined benefit postretirement plans	[1]	0.5	(8.2)	37.4
Other	[1]	1.4	(1.6)	0.2
Total other comprehensive income (loss) attributable to BorgWarner Inc.		232.1	(111.9)	(226.6)
Comprehensive income attributable to BorgWarner Inc.	[1]	672.0	6.6	383.1
Net earnings attributable to the noncontrolling interest, net of tax	[1]	43.4	41.7	36.7
Other comprehensive income (loss) attributable to the noncontrolling interest	[1]	11.4	(5.1)	(5.1)
Comprehensive income		$ 726.8	$ 43.2	$ 414.7

[1] *Net of income taxes.