Significant Accounting Policies - Narrative (Details) $ in Millions	12 Months Ended
	Sep. 30, 2021 USD ($) numberOfSegments numberOfPrincipalActivities	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)
Significant Accounting Policies [Line Items]
Number of principal activities | numberOfPrincipalActivities	3
Number of reportable segments | numberOfSegments	2
Sales	$ 2,981	$ 2,353	$ 2,390
Customer incentives	402	332	346
Reserves for customer programs and incentives	71	64
Shipping and handling costs recorded in sales	10	9	10
Advertising costs	90	72	73
Research and development costs	$ 15	13	13
Transferred at Point in Time [Member]
Significant Accounting Policies [Line Items]
Percentage of revenue recognized	98.00%
Sales	$ 2,931	2,313	2,347
Transferred over Time [Member]
Significant Accounting Policies [Line Items]
Sales	$ 50	40	$ 43
Accounting Standards Update 2016-13
Significant Accounting Policies [Line Items]
Accounts Receivable, Allowance for Credit Loss		$ 2
Minimum
Significant Accounting Policies [Line Items]
Payment terms	30 days
Expected timing of satisfaction for revenue performance obligations	10 years
Minimum | Buildings
Significant Accounting Policies [Line Items]
Estimated useful life of property, plant and equipment	10 years
Minimum | Machinery and Equipment [Member]
Significant Accounting Policies [Line Items]
Estimated useful life of property, plant and equipment	2 years
Maximum
Significant Accounting Policies [Line Items]
Payment terms	60 days
Expected timing of satisfaction for revenue performance obligations	15 years
Maximum | Buildings
Significant Accounting Policies [Line Items]
Estimated useful life of property, plant and equipment	25 years
Maximum | Machinery and Equipment [Member]
Significant Accounting Policies [Line Items]
Estimated useful life of property, plant and equipment	30 years