BorgWarner Inc. and Consolidated Subsidiaries Consolidated Statements of Equity and Comprehensive Income (USD $) In Millions, except Share data, unless otherwise specified	Total	Common Stock [Member]	Treasury Stock [Member]	Capital in excess of par value [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Equity Attributable Noncontrolling interests [Member]	Comprehensive Income [Member]
Beginning Balance at Dec. 31, 2008		$ 1.2	$ (87.4)	$ 977.6	$ 1,200.5	$ (85.9)	$ 31.5
Beginning Balance, shares at Dec. 31, 2008		117,699,542	(2,167,170)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends declared					(13.8)		(8.8)
Stock option expense				7.2
Stock incentive plans			16.2	(0.7)	(7.0)
Shares outstanding under option, exercised			380,499
Executive stock plan			13.3	6.0	(13.3)
Executive stock plan, shares		0	287,816
Net issuance of restricted stock, less amortization				14.8
Net issuance of restricted stock, less amortization, shares		636,868
Convertible bond issuance				34.7
Convertible bond - Hedge				(36.7)
Convertible bond - Warrant				31.2
Net earnings	36.4				36.4		9.4	36.4
Net earnings attributable to the noncontrolling interest, net of tax	(9.4)				(9.4)			(9.4)
Defined benefit post employment plans, net of tax						(3.4)		(3.4)
Currency translation and hedge instruments, net						99.9	1.9	99.9
Comprehensive income (loss) attributable to noncontrolling interest	3.9					3.9		3.9
Proceeds from Noncontrolling Interests	0
Increase in noncontrolling interest							3.4
Ending Balance at Dec. 31, 2009		1.2	(57.9)	1,034.1	1,193.4	14.5	37.4	127.4
Ending Balance, shares at Dec. 31, 2009		118,336,410	(1,498,855)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends declared							(9.5)
Stock option expense				0.1
Stock incentive plans			22.6	43.5	(10.6)
Shares outstanding under option, exercised			525,297
Executive stock plan			11.5	3.8	0
Executive stock plan, shares		0	269,896
Net issuance of restricted stock, less amortization				18.9
Net issuance of restricted stock, less amortization, shares		1,749,796
Purchases of treasury stock			(325.7)
Purchases of treasury stock, shares			(7,066,100)
Net earnings	396.2				396.2		18.8	396.2
Net earnings attributable to the noncontrolling interest, net of tax	(18.8)				(18.8)			(18.8)
Defined benefit post employment plans, net of tax						7.8		7.8
Net unrealized gain/loss on available-for-sale securities						1.2		1.2
Currency translation and hedge instruments, net						(77.1)	2.5	(77.1)
Comprehensive income (loss) attributable to noncontrolling interest	(0.1)					(0.1)		(0.1)
Proceeds from Noncontrolling Interests	0
Increase in noncontrolling interest							2.0
Ending Balance at Dec. 31, 2010	2,309.8	1.2	(349.5)	1,100.4	1,560.2	(53.7)	51.2	309.2
Ending Balance, shares at Dec. 31, 2010		120,086,206	(7,769,762)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends declared							(22.0)
Stock incentive plans				38.7
Shares outstanding under option, exercised		1,020,375
Executive stock plan				6.8
Executive stock plan, shares		104,205
Net issuance of restricted stock, less amortization				15.0
Net issuance of restricted stock, less amortization, shares		104,919
Purchases of treasury stock			(357.6)
Purchases of treasury stock, shares			(5,031,481)
Net earnings	570.6				570.6		20.5	570.6
Net earnings attributable to the noncontrolling interest, net of tax	(20.5)				(20.5)			(20.5)
Defined benefit post employment plans, net of tax						(27.6)		(27.6)
Net unrealized gain/loss on available-for-sale securities						(0.1)		(0.1)
Currency translation and hedge instruments, net						(65.9)	(1.3)	(65.9)
Comprehensive income (loss) attributable to noncontrolling interest	(2.0)					(2.0)		(2.0)
Proceeds from Noncontrolling Interests	19.5						19.5
Other comprehensive income (loss), pension and other postretirement benefit plans, acquired, net of tax						(1.5)		(1.5)
Purchase of subsidiary shares from noncontrolling interest							(2.8)
Dytech ENSA, S.L. Acquisition							0
Adjustments to capital in excess of par value				(26.6)
Ending Balance at Dec. 31, 2011	$ 2,453.0	$ 1.2	$ (707.1)	$ 1,134.3	$ 2,110.3	$ (150.8)	$ 65.1	$ 453.0
Ending Balance, shares at Dec. 31, 2011		121,315,705	(12,801,243)