Recent Transactions (Details) - USD ($) $ in Millions			1 Months Ended	3 Months Ended			12 Months Ended
	Oct. 30, 2019	Jan. 02, 2019	Dec. 31, 2018	Mar. 31, 2019	Sep. 30, 2018	Dec. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Sep. 30, 2019	Jun. 30, 2019	May 31, 2019	Sep. 27, 2017
Business Acquisition [Line Items]
Gain on derecognition of subsidiary	$ 177						$ 177	$ 0	$ 0
Business acquisition, percentage of voting interests acquired										20.00%	20.00%
Payments for businesses acquired, net of cash acquired							10	0	186
Goodwill			$ 1,853				1,842	1,853
Proceeds from sale of businesses, net of cash divested							24	0	0
Noncontrolling Interest, Decrease from Deconsolidation								0
Proceeds from Divestiture of Businesses			28
Asset impairment and loss on divestiture							7	26	71
Assets			10,095			$ 9,788	9,702	10,095	$ 9,788
Inventories, net			781				$ 807	$ 781
Romeo Systems Inc. [Member]
Business Acquisition [Line Items]
Equity Securities without Readily Determinable Fair Value, Amount												$ 50
Rinehart Motion Systems LLC and AM Racing LLC [Member]
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross				$ 10
Business Combination, Contingent Consideration, Liability		$ 5
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net		2
Business Combination, Consideration Transferred		$ 15
Sevcon, Inc [Member]
Business Acquisition [Line Items]
Business Acquisition, Effective Date of Acquisition									Sep. 27, 2017
Business acquisition, percentage of voting interests acquired													100.00%
Payments for businesses acquired, net of cash acquired									$ 186
Business Combination, Consideration Transferred, Liabilities Incurred									27
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables													$ 16
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Inventory													17
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Other													3
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment													7
Goodwill													128
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles													71
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities Noncurrent													(9)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Other													(1)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Assets and Liabilities													(3)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accounts Payable													(25)
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net													204
Liabilities assumed from businesses acquired													18
Goodwill, Purchase Accounting Adjustments					$ (6)
Business Combination, Consideration Transferred						5
Customer Relationships [Member] | Sevcon, Inc [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill													18
Developed Technology Rights [Member] | Sevcon, Inc [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill													49
Trade Names [Member] | Sevcon, Inc [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill													$ 4
Minimum [Member]
Business Acquisition [Line Items]
Amortized intangible assets, useful life							3 years
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life								7 years
Minimum [Member] | Rinehart Motion Systems LLC and AM Racing LLC [Member]
Business Acquisition [Line Items]
Amortized intangible assets, useful life		2 years
Maximum [Member]
Business Acquisition [Line Items]
Amortized intangible assets, useful life							20 years
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life								20 years
Maximum [Member] | Rinehart Motion Systems LLC and AM Racing LLC [Member]
Business Acquisition [Line Items]
Amortized intangible assets, useful life		15 years
Romeo Systems Inc. [Member]
Business Acquisition [Line Items]
Ownership interest (percent)												20.00%
BorgWarner Romeo Power LLC [Member] | Corporate Joint Venture [Member]
Business Acquisition [Line Items]
Equity Securities without Readily Determinable Fair Value, Amount												$ 10
Noncontrolling Interest, Ownership Percentage by Parent										60.00%
Drivetrain [Member]
Business Acquisition [Line Items]
Goodwill			1,012			1,024	$ 1,007	$ 1,012	1,024
Assets			$ 3,920			$ 3,904	$ 4,075	$ 3,920	$ 3,904
Drivetrain [Member] | Rinehart Motion Systems LLC and AM Racing LLC [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill		$ 5
Goodwill		$ 7
BorgWarner Morse TEC LLC [Member]
Business Acquisition [Line Items]
Ownership Percentage Transferred	100.00%
Cash payments on transfer of subsidiary to third party	$ (172)
Receivables, net transferred to third party	(9)
Investments and other long-term receivables transferred to third party	(371)
Other non-current assets transferred to third party	(223)
Accounts payable and accrued expenses transferred to third party	7
Asbestos-relates and environmental liabilities transferred to third party	772
Tax expense on derecognition of subsidiary	173
After-tax gain of derecognition of subsidiary	$ 4