BorgWarner Inc. and Consolidated Subsidiaries Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement [Abstract]
Net sales	$ 9,799.3	$ 9,071.0	$ 8,023.2
Cost of sales	7,679.2	7,137.9	6,320.1
Gross profit	2,120.1	1,933.1	1,703.1
Selling, general and administrative expenses	898.5	817.5	662.0
Other expense, net	144.5	137.5	152.8
Operating income	1,077.1	978.1	888.3
Equity in affiliates’ earnings, net of tax	(51.2)	(42.9)	(40.0)
Interest income	(5.8)	(6.3)	(7.5)
Interest expense and finance charges	70.5	84.6	60.4
Earnings before income taxes and noncontrolling interest	1,063.6	942.7	875.4
Provision for income taxes	580.3	306.0	261.5
Net earnings	483.3	636.7	613.9
Net earnings attributable to the noncontrolling interest, net of tax	43.4	41.7	36.7
Net earnings attributable to BorgWarner Inc.	$ 439.9	$ 595.0	$ 577.2
Earnings per share — basic	$ 2.09	$ 2.78	$ 2.57
Earnings per share — diluted	$ 2.08	$ 2.76	$ 2.56
Weighted average shares outstanding (thousands):
Basic	210,429	214,374	224,414
Diluted	211,548	215,328	225,648
Dividends declared per share	$ 0.59	$ 0.53	$ 0.52