Share-Based Compensation Summary of SARs Exercised (Details) - USD ($) $ in Millions	12 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Share-based Payment Arrangement [Abstract]
Total intrinsic value of SARs exercised	$ 212	$ 260	$ 333
Total fair value of SARs vested	$ 46	$ 66	$ 107

The total accumulated difference between fair values of underlying shares on dates of exercise and exercise price on stock appreciation rights which were exercised during the reporting period under the plan.

No definition available.

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