BorgWarner Inc. and Consolidated Subsidiaries Consolidated Statements of Equity - USD ($) $ in Millions	Total		Issued common stock	Capital in excess of par value	Common stock held in treasury	Retained earnings	Accumulated other comprehensive income (loss)	Noncontrolling interests	Employee Stock Option [Member] Common stock held in treasury	Performance Shares [Member] Common stock held in treasury	Restricted Stock [Member] Common stock held in treasury
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Treasury Stock, Common, Shares					(19,960,537)
Beginning Balance at Dec. 31, 2014			$ 2.5	$ 1,112.4	$ (832.2)	$ 3,717.1	$ (383.6)	$ 74.7
Beginning Balance, shares at Dec. 31, 2014			246,390,620
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends declared						(116.7)		(28.5)
Stock incentive plans				(1.8)					$ 18.6
Stock incentive plans, shares	440,000
Net issuance for executive stock plan				2.4						$ 0.0
Net issuance of restricted stock				(3.3)							$ 18.2
Net issuance of restricted stock, shares			(3,563)
Treasury stock reissued, shares									439,653	0	532,951
Purchase of treasury stock					$ (363.0)
Purchases of treasury stock, shares					(8,074,303)
Net earnings attributable to BorgWarner Inc.	$ 609.7					609.7
Net earnings attributable to the noncontrolling interest, net of tax	36.7	[1]						36.7
Other comprehensive income (loss)	(226.6)						(226.6)
Other comprehensive income (loss) attributable to the noncontrolling interest	$ (5.1)	[1]						(5.1)
Ending Balance at Dec. 31, 2015			$ 2.5	1,109.7	$ (1,158.4)	4,210.1	(610.2)	77.8
Ending Balance, shares at Dec. 31, 2015			246,387,057
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Treasury Stock, Common, Shares					(27,062,236)
Dividends declared						(113.4)		(26.0)
Stock incentive plans				(19.4)					$ 32.4
Stock incentive plans, shares	794,000
Net issuance for executive stock plan				12.8						$ 0.0
Net issuance of restricted stock				1.2							$ 19.2
Treasury stock reissued, shares									793,230		414,464
Purchase of treasury stock					$ (274.8)
Business divestiture	$ (4.8)
Purchases of treasury stock, shares					(8,269,550)
Net earnings attributable to BorgWarner Inc.	118.5					118.5
Net earnings attributable to the noncontrolling interest, net of tax	41.7	[1]						41.7
Other comprehensive income (loss)	(111.9)						(111.9)
Other comprehensive income (loss) attributable to the noncontrolling interest	(5.1)	[1]						(5.1)
Ending Balance at Dec. 31, 2016	$ 3,301.9		$ 2.5	1,104.3	$ (1,381.6)	4,215.2	(722.1)	83.6
Ending Balance, shares at Dec. 31, 2016			246,387,057
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Treasury Stock, Common, Shares					(34,124,092)
Dividends declared						(124.1)		(29.3)
Stock incentive plans				(10.6)					$ 18.9
Stock incentive plans, shares	473,000
Net issuance for executive stock plan				21.0						$ 2.7
Net issuance of restricted stock				4.0							$ 14.6
Treasury stock reissued, shares									473,419	73,935	402,184
Purchase of treasury stock					$ (100.0)
Purchases of treasury stock, shares					(2,399,710)
Net earnings attributable to BorgWarner Inc.	$ 439.9					439.9
Net earnings attributable to the noncontrolling interest, net of tax	43.4	[1]						43.4
Other comprehensive income (loss)	232.1						232.1
Other comprehensive income (loss) attributable to the noncontrolling interest	11.4	[1]						11.4
Ending Balance at Dec. 31, 2017	$ 3,825.9		$ 2.5	$ 1,118.7	$ (1,445.4)	$ 4,531.0	$ (490.0)	$ 109.1
Ending Balance, shares at Dec. 31, 2017			246,387,057
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Treasury Stock, Common, Shares					(35,574,264)

[1] *Net of income taxes.