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 (restated)(a)	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)
Net earnings attributable to BorgWarner Inc.	$ 577.2					$ 577.2
Beginning Balance at Dec. 31, 2014			$ 2.5	$ 1,112.4	$ (832.2)	3,273.1	$ (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
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 the noncontrolling interest, net of tax	36.7							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)	3,733.6	(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)
Net earnings attributable to BorgWarner Inc.	595.0					595.0
Dividends declared						(113.4)		(26.0)
Stock incentive plans				(19.4)					$ 32.4
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 the noncontrolling interest, net of tax	41.7							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)
Net earnings attributable to BorgWarner Inc.	439.9					439.9
Dividends declared						(124.1)		(29.3)
Stock incentive plans				(10.6)					$ 18.9
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 the noncontrolling interest, net of tax	43.4							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.