Reporting Segments (Details) $ in Millions		3 Months Ended
		Mar. 31, 2016 USD ($) segment	Mar. 31, 2015 USD ($)	Dec. 31, 2015 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment		2
Net Sales by Reporting Segment
Segment Reporting, Entity Consolidated Revenue		$ 2,268.6	$ 1,984.2
Adjusted earnings before interest, income taxes and noncontrolling interest
Adjusted EBIT		317.2	301.4
Restructuring expense		6.4	12.1
Merger and acquisition expense		5.8	0.0
Gain on previously held equity interest		0.0	(10.8)
Corporate, including equity in affiliates' earnings and stock-based compensation		31.7	32.0
Interest income		(1.6)	(1.7)
Interest expense and finance charges		21.3	10.0
Earnings before income taxes and noncontrolling interest		253.6	259.8
Provision for income taxes		80.4	72.1
Net earnings		173.2	187.7
Net earnings attributable to the noncontrolling interest, net of tax		9.1	8.8
Net earnings attributable to BorgWarner Inc.		164.1	178.9
Segment Reporting Information - Assets
Total assets		8,940.7		$ 8,825.7
Operating Segments [Member]
Segment Reporting Information - Assets
Total assets		7,952.4		7,703.1
Engine [Member]
Net Sales by Reporting Segment
Segment Reporting, Entity Consolidated Revenue		1,399.2	1,380.9
Adjusted earnings before interest, income taxes and noncontrolling interest
Adjusted EBIT		233.4	230.4
Segment Reporting Information - Assets
Total assets		4,211.6		4,018.0
Drivetrain [Member]
Net Sales by Reporting Segment
Segment Reporting, Entity Consolidated Revenue		879.2	611.2
Adjusted earnings before interest, income taxes and noncontrolling interest
Adjusted EBIT		83.8	71.0
Segment Reporting Information - Assets
Total assets		3,740.8		3,685.1
Intersegment Eliminations [Member]
Net Sales by Reporting Segment
Segment Reporting, Entity Consolidated Revenue		(9.8)	(7.9)
Corporate Segment [Member]
Segment Reporting Information - Assets
Total assets	[1]	988.3		$ 1,122.6
BERU Diesel Start Systems Pvt. Ltd.
Adjusted earnings before interest, income taxes and noncontrolling interest
Gain on previously held equity interest		$ 0.0	$ (10.8)

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