Reporting Segments (Details) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2016 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2016 USD ($) segment	Jun. 30, 2015 USD ($)	Dec. 31, 2015 USD ($)
Segment Reporting Information [Line Items]
Sales Revenue, Goods, Net		$ 2,329.2	$ 2,031.9	$ 4,597.8	$ 4,016.1
Number of reportable segments | segment				2
Adjusted earnings before interest, income taxes and noncontrolling interest
Adjusted EBIT		327.6	300.1	$ 644.8	601.5
Restructuring expense		19.2	19.9	25.6	32.0
Merger and acquisition expense		7.2	0.0	13.0	0.0
Contract expiration gain		(7.5)	0.0	(7.5)	0.0
Gain on previously held equity interest				0.0	(10.8)
Corporate, including equity in affiliates' earnings and stock-based compensation		29.2	26.6	60.9	58.6
Interest income		(1.5)	(1.6)	(3.1)	(3.3)
Interest expense and finance charges		21.4	17.6	42.7	27.6
Earnings before income taxes and noncontrolling interest		259.6	237.6	513.2	497.4
Provision for income taxes		84.2	80.2	164.6	152.3
Net earnings		175.4	157.4	348.6	345.1
Net earnings attributable to the noncontrolling interest, net of tax		11.0	9.3	20.1	18.1
Net earnings attributable to BorgWarner Inc.		164.4	148.1	328.5	327.0
Segment Reporting Information - Assets
Total assets		8,988.6		8,988.6		$ 8,825.7
Operating Segments [Member]
Segment Reporting Information - Assets
Total assets		7,888.9		7,888.9		7,703.1
Engine [Member]
Segment Reporting Information [Line Items]
Sales Revenue, Goods, Net		1,444.2	1,413.0	2,843.4	2,793.9
Adjusted earnings before interest, income taxes and noncontrolling interest
Adjusted EBIT		234.8	228.0	468.2	458.4
Segment Reporting Information - Assets
Total assets		4,172.2		4,172.2		4,018.0
Drivetrain [Member]
Segment Reporting Information [Line Items]
Sales Revenue, Goods, Net		895.4	626.9	1,774.6	1,238.1
Adjusted earnings before interest, income taxes and noncontrolling interest
Adjusted EBIT		92.8	72.1	176.6	143.1
Segment Reporting Information - Assets
Total assets		3,716.7		3,716.7		3,685.1
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Sales Revenue, Goods, Net		(10.4)	(8.0)	(20.2)	(15.9)
BERU Diesel Start Systems Pvt. Ltd.
Adjusted earnings before interest, income taxes and noncontrolling interest
Gain on previously held equity interest		0.0	$ 0.0	0.0	$ (10.8)
Corporate, Non-Segment [Member]
Segment Reporting Information - Assets
Total assets	[1]	$ 1,099.7		$ 1,099.7		$ 1,122.6

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