CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019		Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net earnings		$ 500	$ 746		$ 931
Other comprehensive income (loss)
Foreign currency translation adjustments*	[1]	176	(55)		(148)
Hedge instruments	[1]	0	0		2
Defined benefit postretirement plans	[1]	(100)	4		(23)
Other	[1]	0	(2)		(1)
Total other comprehensive income (loss) attributable to BorgWarner Inc.		76	(53)		(170)
Comprehensive income attributable to BorgWarner Inc	[1]	576	693		761
Net earnings attributable to the noncontrolling interest, net of tax	[1]	67	51		54
Other comprehensive (loss) income attributable to the noncontrolling interest		20	(2)	[1]	(8)	[1]
Comprehensive income		$ 663	$ 742		$ 807

[1] Net of income taxes.