Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Statement [Abstract]
Net sales	$ 2,478.5	$ 2,416.2	$ 7,956.8	$ 7,212.9
Cost of sales	1,962.9	1,894.6	6,270.2	5,662.1
Gross profit	515.6	521.6	1,686.6	1,550.8
Selling, general and administrative expenses	230.5	225.0	719.9	659.1
Other expense, net	7.1	22.0	42.4	27.5
Operating income	278.0	274.6	924.3	864.2
Equity in affiliates’ earnings, net of tax	(15.2)	(14.4)	(38.4)	(38.5)
Interest income	(1.5)	(1.3)	(4.4)	(4.2)
Interest expense and finance charges	14.4	17.6	45.4	53.6
Other postretirement income	(2.4)	(1.3)	(7.4)	(3.9)
Earnings before income taxes and noncontrolling interest	282.7	274.0	929.1	857.2
Provision for income taxes	66.8	79.4	192.1	241.9
Net earnings	215.9	194.6	737.0	615.3
Net earnings attributable to the noncontrolling interest, net of tax	12.1	9.7	36.3	29.2
Net earnings attributable to BorgWarner Inc.	$ 203.8	$ 184.9	$ 700.7	$ 586.1
Earnings per share — basic	$ 0.98	$ 0.88	$ 3.36	$ 2.78
Earnings per share — diluted	$ 0.98	$ 0.88	$ 3.34	$ 2.77
Weighted average shares outstanding (thousands):
Basic	207,471	209,803	208,505	210,657
Diluted	208,738	211,013	209,787	211,575
Dividends declared per share	$ 0.17	$ 0.14	$ 0.51	$ 0.42