Segments (Acquisition and Integration Costs and Revenue from External Customers by Products and Services) (Details) - USD ($)	3 Months Ended	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Revenue from External Customer [Line Items]
Acquisition and integration costs (pre-tax)		$ 0	$ 16,500,000	$ 68,900,000
Business exit charges		0	7,500,000	0
Gain on finance lease termination	$ 0	0	4,500,000	0
Depreciation and amortization		122,700,000	121,600,000	118,500,000
Amortization of intangible assets		59,400,000	61,100,000	61,200,000
Segments
Revenue from External Customer [Line Items]
Depreciation and amortization		63,300,000	60,500,000	57,300,000
Segments | Batteries & Lights
Revenue from External Customer [Line Items]
Depreciation and amortization		52,200,000	50,600,000	49,000,000.0
Segments | Auto Care
Revenue from External Customer [Line Items]
Depreciation and amortization		11,100,000	9,900,000	8,300,000
Segment Reconciling Items
Revenue from External Customer [Line Items]
Business exit charges		0	(14,600,000)	0
Gain on finance lease termination		0	4,500,000	0
Cost of products sold
Revenue from External Customer [Line Items]
Acquisition and integration costs (pre-tax)		0	6,000,000.0	33,700,000
Business exit charges		1,300,000
SG&A
Revenue from External Customer [Line Items]
Acquisition and integration costs (pre-tax)		0	9,400,000	40,000,000.0
Business exit charges		5,800,000
Research and development
Revenue from External Customer [Line Items]
Acquisition and integration costs (pre-tax)		0	1,100,000	1,100,000
Other items, net
Revenue from External Customer [Line Items]
Gain/expense reclassified to acquisitions and integration costs			(5,900,000)
Other Comprehensive Income (Loss)
Revenue from External Customer [Line Items]
Other items, net		$ 0	$ 0	$ (5,900,000)