Maximum Line Of Credit Potential Additional Increase

No definition available.

Name:	bwa_MaximumLineOfCreditPotentialAdditionalIncrease
Namespace Prefix:	bwa_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
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+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=121572278&loc=d3e13433-108611

+ Details

Name:	us-gaap_DebtInstrumentFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Weighted average interest rate of debt outstanding.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

Name:	us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

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+ Details

Name:	us-gaap_LineOfCredit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_LineOfCreditFacilityLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)(3)
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+ Details

Name:	us-gaap_LongTermDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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-SubTopic 10
-Section S99
-Paragraph 1
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+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Weighted average interest rate of short-term debt outstanding calculated at point in time.

+ References

+ Details

Name:	us-gaap_ShortTermDebtWeightedAverageInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Details

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- Details

Name:	us-gaap_FairValueByMeasurementBasisAxis=us-gaap_ChangeDuringPeriodFairValueDisclosureMember
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Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=us-gaap_RevolvingCreditFacilityMember
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Balance Type:
Period Type:

- Details

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- Details

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Notes Payable and Long-Term Debt - Narrative (Details) - USD ($)	Oct. 01, 2020	Sep. 30, 2020	Jun. 19, 2020	Apr. 29, 2020	Mar. 13, 2020	Mar. 12, 2020	Dec. 31, 2019
Line of Credit Facility
Short-term borrowings		$ 47,000,000					$ 34,000,000
Short-term debt, weighted average interest rate, at point in time (in percent)		2.20%					2.50%
Debt weighted average interest rate (in percent)		2.30%					2.80%
Long-term debt		$ 2,789,000,000					$ 1,926,000,000
Letters of credit outstanding, amount		32,000,000					28,000,000
Estimate of Fair Value Measurement
Line of Credit Facility
Estimated fair value of senior unsecured notes		3,027,000,000					2,025,000,000
Change in Measurement
Line of Credit Facility
Estimated fair value of senior unsecured notes		245,000,000					106,000,000
Revolving Credit Facility
Line of Credit Facility
Maximum borrowing capacity					$ 1,500,000,000	$ 1,200,000,000
Potential additional increase to credit facility					$ 1,000,000,000.0
Line of credit outstanding		0					0
Revolving Credit Facility \| Subsequent Event
Line of Credit Facility
Maximum borrowing capacity	$ 2,000,000,000.0
Short-term, Unsecured Commercial Paper Notes
Line of Credit Facility
Maximum borrowing capacity		1,500,000,000
Line of credit outstanding		0					0
Short-term, Unsecured Commercial Paper Notes \| Subsequent Event
Line of Credit Facility
Maximum borrowing capacity	$ 2,000,000,000.0
Senior Notes \| 4.625% Senior notes due 09/15/20 ($250 million par value)
Line of Credit Facility
Long-term debt		$ 0	$ 250,000,000				251,000,000
Debt instrument stated interest rate (in percent)		4.625%	4.625%
Debt instrument face value		$ 250,000,000
Senior Notes \| 2.650% Senior notes due 07/01/27 ($1,100 million par value)
Line of Credit Facility
Long-term debt		$ 1,088,000,000					$ 0
Debt instrument stated interest rate (in percent)		2.65%	2.65%
Debt instrument face value		$ 1,100,000,000	$ 1,100,000,000
Term loan \| Delay Draw Term Loan
Line of Credit Facility
Debt instrument face value				$ 750,000,000