Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Statement [Abstract]
Net sales	$ 2,492.0	$ 2,478.0	$ 7,609.0	$ 7,956.0
Cost of sales	1,968.0	1,963.0	6,053.0	6,270.0
Gross profit	524.0	515.0	1,556.0	1,686.0
Selling, general and administrative expenses	230.0	230.0	668.0	720.0
Other expense, net	18.0	7.0	63.0	42.0
Operating income	276.0	278.0	825.0	924.0
Equity in affiliates’ earnings, net of tax	(7.0)	(15.0)	(25.0)	(38.0)
Interest income	(4.0)	(1.0)	(9.0)	(4.0)
Interest expense	15.0	14.0	43.0	45.0
Other postretirement (income) expense	(1.0)	(3.0)	26.0	(8.0)
Earnings before income taxes and noncontrolling interest	273.0	283.0	790.0	929.0
Provision for income taxes	66.0	67.0	230.0	192.0
Net earnings	207.0	216.0	560.0	737.0
Net earnings attributable to the noncontrolling interest, net of tax	13.0	12.0	34.0	36.0
Net earnings attributable to BorgWarner Inc.	$ 194.0	$ 204.0	$ 526.0	$ 701.0
Earnings per share — basic	$ 0.94	$ 0.98	$ 2.56	$ 3.36
Earnings per share — diluted	$ 0.94	$ 0.98	$ 2.54	$ 3.34
Weighted Average Number of Shares Outstanding [Abstract]
Basic	205.3	207.5	205.9	208.5
Diluted	206.3	208.7	206.8	209.8