Stockholders' Equity (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Increase (Decrease) in Stockholders' Equity
Beginning balance			$ 4,844
Other comprehensive income (loss)	$ (70)	$ 184	(10)	$ 355
Net earnings attributable to the noncontrolling interest, net of tax	14	10	22	21
Net (loss) earnings attributable to BorgWarner Inc.	(98)	$ 172	31	332
Ending balance	$ 4,763		$ 4,763
Dividends declared (in dollar per share)	$ 0.17	$ 0.17	$ 0.17
Issued common stock
Increase (Decrease) in Stockholders' Equity
Beginning balance	$ 3	$ 3	$ 3	3
Ending balance	3	3	3	3
Capital in excess of par value
Increase (Decrease) in Stockholders' Equity
Beginning balance	1,109	1,111	1,145	1,146
Net issuance for executive stock plan		1	(16)	(9)
Net issuance of restricted stock	6	4	(14)	(21)
Ending balance	1,115	1,116	1,115	1,116
Treasury stock
Increase (Decrease) in Stockholders' Equity
Beginning balance	(1,623)	(1,626)	(1,657)	(1,585)
Net issuance for executive stock plan			12	7
Net issuance of restricted stock		4	22	25
Purchase of treasury stock		(31)		(100)
Ending balance	(1,623)	(1,653)	(1,623)	(1,653)
Retained earnings
Increase (Decrease) in Stockholders' Equity
Beginning balance	6,036	5,461	5,942	5,336
Dividends declared	(35)	(35)	(70)	(70)
Net (loss) earnings attributable to BorgWarner Inc.	(98)	172	31	332
Ending balance	5,903	5,598	5,903	5,598
Accumulated other comprehensive income (loss)
Increase (Decrease) in Stockholders' Equity
Beginning balance	(801)	(675)	(727)	(674)
Other comprehensive income (loss)	14	5	(60)	4
Ending balance	(787)	(670)	(787)	(670)
Noncontrolling interests
Increase (Decrease) in Stockholders' Equity
Beginning balance	140	111	138	119
Dividends declared	(2)	(10)	(5)	(30)
Other comprehensive income (loss)		(3)	(3)	(2)
Net earnings attributable to the noncontrolling interest, net of tax	14	10	22	21
Ending balance	$ 152	$ 108	$ 152	$ 108