Segments (Schedule of Assets and Capital Expenditures and Long-Lived Assets and Net Sales by Geographical Area) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2022
Revenues from External Customers and Long-Lived Assets [Line Items]
Assets	$ 4,342.4	$ 4,509.6
Long lived tangible assets	746.6	699.1
Net sales	2,887.0	2,959.7	$ 3,050.1
Depreciation and amortization	120.5	122.7	121.6
Amortization of intangible assets	58.2	59.4	61.1
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Long lived tangible assets	543.8	510.7
Net sales	1,706.3	1,751.1	1,799.5
International
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	1,180.7	1,208.6	1,250.6
Singapore
Revenues from External Customers and Long-Lived Assets [Line Items]
Long lived tangible assets	42.1	56.2
Indonesia
Revenues from External Customers and Long-Lived Assets [Line Items]
Long lived tangible assets	41.3	33.0
United Kingdom
Revenues from External Customers and Long-Lived Assets [Line Items]
Long lived tangible assets	55.4	61.2
Other International
Revenues from External Customers and Long-Lived Assets [Line Items]
Long lived tangible assets	64.0	38.0
Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Assets	1,773.8	1,785.5
Capital expenditures	97.9	56.8	77.8
Depreciation and amortization	62.3	63.3	60.5
Segments | Batteries & Lights
Revenues from External Customers and Long-Lived Assets [Line Items]
Capital expenditures	84.9	47.8	65.8
Depreciation and amortization	50.3	52.2	50.6
Segments | Auto Care
Revenues from External Customers and Long-Lived Assets [Line Items]
Capital expenditures	13.0	9.0	12.0
Depreciation and amortization	12.0	11.1	9.9
Segments | Batteries & Lights
Revenues from External Customers and Long-Lived Assets [Line Items]
Assets	1,421.1	1,362.0
Net sales	2,259.5	2,344.9	2,427.3
Segments | Auto Care
Revenues from External Customers and Long-Lived Assets [Line Items]
Assets	352.7	423.5
Net sales	627.5	614.8	622.8
Corporate
Revenues from External Customers and Long-Lived Assets [Line Items]
Assets	451.7	470.2
Segment Reporting, Reconciling Item, Excluding Corporate Nonsegment
Revenues from External Customers and Long-Lived Assets [Line Items]
Goodwill and other intangible assets, net	2,116.9	2,253.9
Amortization of intangible assets	$ 58.2	$ 59.4	$ 61.1