Reporting Segments (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014 segment		Mar. 31, 2013	Dec. 31, 2013
Segment Reporting Information [Line Items]
Number of reportable segments	2
Net Sales by Reporting Segment
Segment Reporting, Entity Consolidated Revenue	$ 2,084.1		$ 1,851.1
Adjusted earnings before interest, income taxes and noncontrolling interest
Adjusted EBIT	312.2		258.3
Restructuring expense	39.5		0
Program termination agreement	0		11.3
Retirement related obligations	0		5.9
Corporate, including equity in affiliates' earnings and stock-based compensation	30.7		32.9
Interest income	(1.5)		(1.0)
Interest expense and finance charges	8.2		9.7
Earnings before income taxes and noncontrolling interest	235.3		199.5
Provision for income taxes	68.1		50.9
Net earnings	167.2		148.6
Net earnings attributable to the noncontrolling interest, net of tax	8.1		6.6
Net earnings attributable to BorgWarner Inc.	159.1		142.0
Segment Reporting Information - Assets
Total assets	7,357.8			6,917.0
Operating Segments [Member]
Segment Reporting Information - Assets
Total assets	5,866.3			5,305.7
Engine [Member]
Net Sales by Reporting Segment
Segment Reporting, Entity Consolidated Revenue	1,412.1		1,257.5
Adjusted earnings before interest, income taxes and noncontrolling interest
Adjusted EBIT	231.7		202.3
Segment Reporting Information - Assets
Total assets	4,002.5			3,519.1
Drivetrain [Member]
Net Sales by Reporting Segment
Segment Reporting, Entity Consolidated Revenue	680.7		601.4
Adjusted earnings before interest, income taxes and noncontrolling interest
Adjusted EBIT	80.5		56.0
Segment Reporting Information - Assets
Total assets	1,863.8			1,786.6
Intersegment Eliminations [Member]
Net Sales by Reporting Segment
Segment Reporting, Entity Consolidated Revenue	(8.7)		(7.8)
Corporate Segment [Member]
Segment Reporting Information - Assets
Total assets	$ 1,491.5	[1]		$ 1,611.3	[1]

[1] Corporate assets include investments and advances and deferred income taxes.