Acquisition - Narrative (Details) $ / shares in Units, € in Millions, shares in Millions, $ in Millions						3 Months Ended				9 Months Ended
	Jan. 31, 2020 USD ($)	Jan. 02, 2020 EUR (€)	Jan. 28, 2019 USD ($) $ / shares shares	Jan. 02, 2019 USD ($)	Nov. 15, 2018 USD ($)	Jun. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)
Business Acquisition [Line Items]
Payments to acquire business								$ 3.6		$ 4.5	$ 2,453.8
Inventory adjustment									$ 5.0		27.5
Write down of assets of business held for sale											107.2
Gain on sale of assets						$ 0.0			0.0	(1.0)	0.0
Earnings related to transition service agreements						(0.4)			(0.7)	(0.8)	(0.8)
Gain (Loss) Recognized in Income						0.0			0.9	2.2	(8.1)
Interest income on restricted cash						0.0			0.0	0.0	5.8
Fair Value Adjustment to Inventory
Business Acquisition [Line Items]
Acquisition and integration costs						6.5				33.7
Research and Development Expense
Business Acquisition [Line Items]
Acquisition and integration costs						0.2			0.3	1.2	0.3
Interest Expense
Business Acquisition [Line Items]
Interest and other financing items											65.6
Other Items, Net
Business Acquisition [Line Items]
Earnings related to transition service agreements						(0.4)			(13.2)	0.4	(13.2)
Pre-tax expenses									0.2	0.4	0.2
Interest income on restricted cash											(5.8)
Costs of products sold
Business Acquisition [Line Items]
Acquisition and integration costs						5.5			12.4	20.7	44.1
USD Restricted Cash Held in European Euro Functional Entity
Business Acquisition [Line Items]
Pre-tax expenses											1.5
USD Restricted Cash Held in European Euro Functional Entity | Other Items, Net
Business Acquisition [Line Items]
Favorable movement in escrowed USD restricted cash											(9.0)
Disposal Group, Disposed of by Sale, Not Discontinued Operations
Business Acquisition [Line Items]
Initial cash proceeds | €		€ 180.0
Inventory fair value adjustment									11.2		11.2
CAE
Business Acquisition [Line Items]
Payments to acquire business	$ 1.9
Acquisition purchase price	7.0
CAE | Vendor Relationships
Business Acquisition [Line Items]
Intangible asset acquired	5.7
CAE | Certain Financial Metrics
Business Acquisition [Line Items]
Initial cash paid including estimated working capital adjustments	$ 9.9
Spectrum Brands Holdings
Business Acquisition [Line Items]
Payments to acquire business				$ 2,000.0
Initial cash paid including estimated working capital adjustments				1,962.4
Intangible asset acquired				805.8
Cash consideration initially allocated to divested business				400.0
Inventory adjustment								14.6
Inventory fair value adjustment						11.2				11.2
Net assets acquired				$ 1,962.4
Spectrum Auto Care Acquisition
Business Acquisition [Line Items]
Payments to acquire business					$ 937.5
Initial cash paid including estimated working capital adjustments			$ 938.7				$ (3.6)
Acquisition purchase price					1,250.0
Intangible asset acquired			$ 965.3
Inventory adjustment								$ 21.6
Newly-issued common stock in acquisition					$ 312.5					2.0
Newly-issued common stock in acquisition (in shares) | shares			5.3
Fair value of equity consideration			$ 240.5
Opening stock price (in dollars per share) | $ / shares			$ 45.55
Net assets acquired			$ 1,182.8
Battery Acquisition and Auto Care Acquisition
Business Acquisition [Line Items]
Acquisition and integration costs						11.4			28.0	47.6	159.9
Battery Acquisition and Auto Care Acquisition | Selling, General and Administrative Expenses
Business Acquisition [Line Items]
Acquisition and integration costs						$ 6.1			$ 15.1	$ 25.3	$ 63.1