Sale-Type Leases and Financing Receivables Sales-Type Leases and Financing Receivables - Additional Information (Detail) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
Jun. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Receivables [Abstract]
Lessor, Sales-Type Lease, Contract Term	5 years
Lease Contract Modification Related Charge		$ 0	$ 748	$ 0

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

No definition available.

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