Reporting Segments and Related Information - Adjusted EBIT (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Adjusted EBIT									$ 1,288.6	$ 1,195.3	$ 1,227.3
Asbestos-related charge									703.6	0.0	0.0
Loss on divestiture	$ 20.6								127.1	0.0	0.0
Restructuring expense		$ 1.3	$ 19.2	$ 6.4	$ 24.4	$ 6.3	$ 10.5	$ 9.4	26.9	65.7	90.8
Intangible asset impairment									12.6	0.0	10.3
Gain (Loss) on Contract Termination									(6.2)	0.0	0.0
Pension settlement loss									0.0	25.7	3.1
Merger and acquisition expense	4.8	5.9	7.2	5.8	17.9	3.9			23.7	21.8	0.0
Gain on previously held equity interest									0.0	(10.8)	0.0
Corporate, including equity in affiliates' earnings and stock-based compensation									132.1	113.2	112.1
Interest income	(1.6)	(1.6)	(1.5)	(1.6)	(2.2)	(2.0)	(1.6)	(1.7)	(6.3)	(7.5)	(5.5)
Interest expense and finance charges	19.5	22.4	21.4	21.3	17.8	15.0	17.6	10.0	84.6	60.4	36.4
Earnings before income taxes and noncontrolling interest									190.5	926.8	980.1
Provision for income taxes	(183.1)	48.8	84.2	80.4	61.2	66.9	80.2	72.1	30.3	280.4	292.6
Net earnings	(281.5)	93.1	175.4	173.2	135.4	165.9	157.4	187.7	160.2	646.4	687.5
Net earnings attributable to the noncontrolling interest, net of tax	11.8	9.8	11.0	9.1	10.1	8.5	9.3	8.8	41.7	36.7	31.7
Net earnings attributable to BorgWarner Inc.	(293.3)	$ 83.3	$ 164.4	$ 164.1	$ 125.3	$ 157.4	$ 148.1	$ 178.9	118.5	609.7	655.8
Engine [Member]
Segment Reporting Information [Line Items]
Adjusted EBIT									934.1	900.7	924.0
Drivetrain [Member]
Segment Reporting Information [Line Items]
Adjusted EBIT									$ 354.5	$ 294.6	$ 303.3
U.S. Plans:
Segment Reporting Information [Line Items]
Loss on divestiture	$ 20.6