Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Income Statement [Abstract]
Net sales	$ 2,551.0	$ 2,694.0	$ 5,117.0	$ 5,478.0
Cost of sales	2,038.0	2,114.0	4,085.0	4,307.0
Gross profit	513.0	580.0	1,032.0	1,171.0
Selling, general and administrative expenses	212.0	237.0	438.0	490.0
Other expense, net	16.0	30.0	45.0	35.0
Operating income	285.0	313.0	549.0	646.0
Equity in affiliates’ earnings, net of tax	(9.0)	(13.0)	(18.0)	(23.0)
Interest income	(2.0)	(1.0)	(5.0)	(3.0)
Interest expense	14.0	15.0	28.0	31.0
Other postretirement expense (income)	27.0	(2.0)	27.0	(5.0)
Earnings before income taxes and noncontrolling interest	255.0	314.0	517.0	646.0
Provision for income taxes	73.0	30.0	164.0	125.0
Net earnings	182.0	284.0	353.0	521.0
Net earnings attributable to the noncontrolling interest, net of tax	10.0	12.0	21.0	24.0
Net earnings attributable to BorgWarner Inc.	$ 172.0	$ 272.0	$ 332.0	$ 497.0
Earnings per share — basic	$ 0.84	$ 1.30	$ 1.61	$ 2.38
Earnings per share — diluted	$ 0.83	$ 1.30	$ 1.60	$ 2.36
Basic	205.7	208.6	206.1	209.0
Diluted	206.8	209.9	207.0	210.3