Stockholder's Equity (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018	Jan. 01, 2018	Dec. 31, 2017
Common Stock, Dividends, Per Share, Declared		$ 0.17	$ 0.17	$ 0.51	$ 0.51
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest		$ 4,578.0		$ 4,578.0			$ 4,345.0
Contributions from noncontrolling interest stockholders				4.0	$ 0.0
Cumulative Effect of New Accounting Principle in Period of Adoption									$ (14.0)
Net earnings attributable to BorgWarner Inc.		194.0	$ 204.0	526.0	701.0
Net earnings attributable to the noncontrolling interest, net of tax		13.0	12.0	34.0	36.0
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent		(109.0)	(41.0)	(105.0)	(119.0)
Other comprehensive loss attributable to the noncontrolling interest	[1]	(5.0)	(3.0)	(7.0)	(7.0)
Common Stock [Member]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest		3.0	3.0	3.0	3.0	$ 3.0	3.0	$ 3.0		$ 3.0
Additional Paid-in Capital [Member]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest		1,129.0	1,127.0	1,129.0	1,127.0	1,116.0	1,146.0	1,110.0		1,118.0
Treasury Stock [Member]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest		(1,653.0)	(1,581.0)	(1,653.0)	(1,581.0)	(1,653.0)	(1,585.0)	(1,544.0)		(1,445.0)
Treasury Stock, Value, Acquired, Cost Method			(36.0)	(100.0)	(150.0)
Retained Earnings [Member]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest		5,757.0	5,142.0	5,757.0	5,142.0	5,598.0	5,336.0	4,973.0		4,531.0
Dividends, Common Stock, Cash		(35.0)	(35.0)	(105.0)	(106.0)
Cumulative Effect of New Accounting Principle in Period of Adoption									16.0
Net earnings attributable to BorgWarner Inc.		194.0	204.0	526.0	701.0
AOCI Attributable to Parent [Member]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest		(779.0)	(623.0)	(779.0)	(623.0)	(670.0)	(674.0)	(582.0)		(490.0)
Cumulative Effect of New Accounting Principle in Period of Adoption									$ (14.0)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent		(109.0)	(41.0)	(105.0)	(119.0)
Noncontrolling Interest [Member]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest		121.0	104.0	121.0	104.0	$ 108.0	$ 119.0	$ 94.0		$ 109.0
Dividends, Common Stock, Cash		1.0	1.0	(29.0)	(34.0)
Contributions from noncontrolling interest stockholders		4.0		4.0
Net earnings attributable to the noncontrolling interest, net of tax		13.0	12.0	34.0	36.0
Other comprehensive loss attributable to the noncontrolling interest		(5.0)	(3.0)	(7.0)	(7.0)
Performance Shares [Member] | Additional Paid-in Capital [Member]
APIC, Share-based Payment Arrangement, Recognition and Exercise		4.0	9.0	(5.0)	10.0
Performance Shares [Member] | Treasury Stock [Member]
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture		1.0	0.0	8.0	5.0
Restricted Stock [Member] | Additional Paid-in Capital [Member]
APIC, Share-based Payment Arrangement, Recognition and Exercise		9.0	8.0	(12.0)	(1.0)
Restricted Stock [Member] | Treasury Stock [Member]
Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures		$ (1.0)	$ (1.0)	$ 24.0	$ 9.0

[1] Net of income taxes.