Allocations of general and administrative costs to segments for management and external reporting purposes.

No definition available.

Name:	bdx_AllocatedCosts
Namespace Prefix:	bdx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Percent of ownership interest in a business that is sold in a disposal transaction.

+ References

No definition available.

+ Details

Name:	bdx_DisposalGroupIncludingDiscontinuedOperationPercentOfBusinessSold
Namespace Prefix:	bdx_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Charge resulting from a modification to dispensing equipment lease contracts with customers.

+ References

No definition available.

+ Details

Name:	bdx_LeaseContractModificationRelatedCharge
Namespace Prefix:	bdx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Number Of Customer Accounted For Ten Percent Or More Of Revenue

+ References

No definition available.

+ Details

Name:	bdx_NumberOfCustomerAccountedForTenPercentOrMoreOfRevenue
Namespace Prefix:	bdx_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Recognition Of Fair Value Adjustment To Inventory Acquired

+ References

No definition available.

+ Details

Name:	bdx_RecognitionOfFairValueAdjustmentToInventoryAcquired
Namespace Prefix:	bdx_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 45
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=109226348&loc=d3e2420-110228

+ Details

Name:	us-gaap_AssetImpairmentCharges
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of revenue attributable to disposal group, including, but not limited to, discontinued operation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 5B
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109222650&loc=SL51721673-107760

+ Details

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

- Definition

The amount of impairment loss recognized in the period resulting from the write-down of the carrying amount of an intangible asset (excluding goodwill) to fair value.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 3
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16373-109275

+ Details

Name:	us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues.

+ References

No definition available.

+ Details

Name:	us-gaap_NumberOfOperatingSegments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

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

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=bdx_RespiratorySolutionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DisposalGroupClassificationAxis=us-gaap_DisposalGroupHeldforsaleNotDiscontinuedOperationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=bdx_MedicalMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=bdx_LifeSciencesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=bdx_CRBardIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=bdx_InterventionalMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Segment Data - Additional Information (Detail) $ in Millions	12 Months Ended
	Sep. 30, 2018 USD ($) customer segment	Sep. 30, 2017 USD ($) customer	Sep. 30, 2016 USD ($) customer	Oct. 03, 2016
Segment Reporting Information [Line Items]
Number of principal business segments (segments) \| segment	3
Number of customers accounted for 10% or more of revenues (customers) \| customer	0	0	0
Asset Impairment Charges			$ 214
Lease Contract Modification Related Charge	$ 0	$ 748	0
Respiratory Solutions
Segment Reporting Information [Line Items]
Disposal Group, Including Discontinued Operation, Revenue			822
Disposal Group, Held-for-sale, Not Discontinued Operations \| Respiratory Solutions
Segment Reporting Information [Line Items]
Disposal Group, Including Discontinued Operation, Percent Of Business Sold				50.10%
Medical
Segment Reporting Information [Line Items]
AllocatedCosts		166	175
Asset Impairment Charges	58
Life Sciences
Segment Reporting Information [Line Items]
AllocatedCosts		$ 113	$ 95
Impairment of Intangible Assets (Excluding Goodwill)	81
CR Bard Inc [Member]
Segment Reporting Information [Line Items]
Recognition Of Fair Value Adjustment To Inventory Acquired	478
CR Bard Inc [Member] \| Medical
Segment Reporting Information [Line Items]
Recognition Of Fair Value Adjustment To Inventory Acquired	60
CR Bard Inc [Member] \| Interventional
Segment Reporting Information [Line Items]
Recognition Of Fair Value Adjustment To Inventory Acquired	$ 418