Reporting Segments (Details) $ in Millions		3 Months Ended
		Mar. 31, 2017 USD ($) segment	Mar. 31, 2016 USD ($)	Dec. 31, 2016 USD ($)
Segment Reporting Information [Line Items]
Sales Revenue, Goods, Net		$ 2,407.0	$ 2,268.6
Number of reportable segments | segment		2
Adjusted earnings before interest, income taxes and noncontrolling interest
Adjusted EBIT		$ 351.8	323.0
Lease termination settlement		5.3	0.0
Merger and acquisition expense		0.0	5.8
Restructuring expense		0.0	6.4
Corporate, including equity in affiliates' earnings and stock-based compensation		44.1	37.5
Interest income		(1.5)	(1.6)
Interest expense and finance charges		18.0	21.3
Earnings before income taxes and noncontrolling interest		285.9	253.6
Provision for income taxes		86.3	80.4
Net earnings		199.6	173.2
Net earnings attributable to the noncontrolling interest, net of tax		10.4	9.1
Net earnings attributable to BorgWarner Inc.		189.2	164.1
Segment Reporting Information - Assets
Total assets		9,083.7		$ 8,834.7
Operating Segments [Member]
Segment Reporting Information - Assets
Total assets		7,683.2		7,347.0
Engine [Member]
Segment Reporting Information [Line Items]
Sales Revenue, Goods, Net		1,495.4	1,399.2
Adjusted earnings before interest, income taxes and noncontrolling interest
Adjusted EBIT		247.0	236.7
Segment Reporting Information - Assets
Total assets		4,322.4		4,134.6
Drivetrain [Member]
Segment Reporting Information [Line Items]
Sales Revenue, Goods, Net		924.9	879.2
Adjusted earnings before interest, income taxes and noncontrolling interest
Adjusted EBIT		104.8	86.3
Segment Reporting Information - Assets
Total assets		3,360.8		3,212.4
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Sales Revenue, Goods, Net		(13.3)	$ (9.8)
Corporate, Non-Segment [Member]
Segment Reporting Information - Assets
Total assets	[1]	$ 1,400.5		$ 1,487.7

[1] Corporate assets include investments and other long-term receivables and certain deferred income taxes.