Reporting Segments (Details) $ in Millions		3 Months Ended
		Mar. 31, 2019 USD ($) segment	Mar. 31, 2018 USD ($)	Dec. 31, 2018 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment		2
Net Sales by Reporting Segment
Net sales		$ 2,566	$ 2,784
Adjusted earnings before interest, income taxes and noncontrolling interest
Adjusted EBIT		346	401
Restructuring expense		14	8
Merger, acquisition and divestiture expense		1	2
Other expense (income), net		14	(5)
Officer stock awards modification		2	0
Other postretirement income		0	(3)
Corporate, including equity in affiliates' earnings and stock-based compensation		42	53
Interest income		(3)	(2)
Interest expense		14	16
Earnings before income taxes and noncontrolling interest		262	332
Provision for income taxes		91	95
Net earnings		171	237
Net earnings attributable to the noncontrolling interest, net of tax		11	12
Net earnings attributable to BorgWarner Inc.		160	225
Segment Reporting Information - Assets
Total assets		10,104		$ 10,095
Operating Segments [Member]
Segment Reporting Information - Assets
Total assets		8,842		8,651
Engine [Member]
Net Sales by Reporting Segment
Net sales		1,598	1,716
Adjusted earnings before interest, income taxes and noncontrolling interest
Adjusted EBIT		241	280
Segment Reporting Information - Assets
Total assets		4,824		4,731
Drivetrain [Member]
Net Sales by Reporting Segment
Net sales		982	1,083
Adjusted earnings before interest, income taxes and noncontrolling interest
Adjusted EBIT		105	121
Restructuring expense			2
Segment Reporting Information - Assets
Total assets		4,018		3,920
Intersegment Eliminations [Member]
Net Sales by Reporting Segment
Net sales		(14)	$ (15)
Corporate, Non-Segment [Member]
Adjusted earnings before interest, income taxes and noncontrolling interest
Restructuring expense		3
Segment Reporting Information - Assets
Total assets	[1]	$ 1,262		$ 1,444

[1] Corporate assets include investments and other long-term receivables and certain deferred income taxes.