Financial Instruments - Income Statement (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Derivative Instruments, Gain (Loss) [Line Items]
Market value of hedge instruments	$ 1.5	$ (25.8)
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months	1.7
Foreign currency contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Market value of hedge instruments	1.3	(3.7)
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months	1.7
Foreign currency contracts [Member] \| Sales [Member]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net [Abstract]
Gain (loss) reclassified from AOCI to income (effective portion)	1.2	1.7
Foreign currency contracts [Member] \| Selling general and administrative expenses [Member]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net [Abstract]
Gain (loss) reclassified from AOCI to income (effective portion)	(0.8)	(0.4)
Gain (loss) recognized in income (ineffective portion)	0.2	0.2
Foreign currency contracts [Member] \| Cost of goods sold [Member]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net [Abstract]
Gain (loss) reclassified from AOCI to income (effective portion)	(1.0)	(13.9)
Foreign currency contracts [Member] \| Selling general and administrative expenses One [Member]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net [Abstract]
Gain (loss) recognized in income (ineffective portion)		(1.5)
Net investment hedge contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Market value of hedge instruments	0.2	(22.1)
Net investment hedge contracts [Member] \| Interest expense [Member]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net [Abstract]
Gain (loss) recognized in income (ineffective portion)	$ (0.7)	$ 1.3

Accumulated other comprehensive income (loss), cumulative change in cash flow hedges, before tax

No definition available.

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

- Definition

The estimated net amount of existing gains or losses on cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 30

-Section 50

-Paragraph 1

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=35736893&loc=d3e80748-113994

+ Details

Name:	us-gaap_CashFlowHedgeGainLossToBeReclassifiedWithinTwelveMonths
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

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

- Definition

The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4C

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5624171-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4D

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5624177-113959

+ Details

Name:	us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

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

- Definition

The portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments representing (a) the amount of the hedge ineffectiveness and (b) the amount, if any, excluded from the assessment of hedge effectiveness.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4C

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5624171-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 25

-Section 50

-Paragraph 1

-Subparagraph (a)(1),(2)

-URI http://asc.fasb.org/extlink&oid=6886632&loc=d3e76258-113986

+ Details

Name:	us-gaap_DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_ForeignExchangeContractMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_NetInvestmentHedgingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: