Acquisition - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions					3 Months Ended				6 Months Ended
	Jan. 28, 2019	Jan. 02, 2019	Nov. 15, 2018	Jul. 02, 2018	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018	Jan. 31, 2019	Jan. 31, 2018	Jan. 15, 2018
Business Acquisition [Line Items]
Payments to acquire business									$ 2,403.8	$ 0.0
Inventory adjustment						$ 22.5		$ 0.0	22.0	(26.5)
Inventory fair value adjustment						11.2			11.2
Cost to sell									107.2
Acquisition and integration costs						95.4		19.4
Settlement of acquired business hedging contracts						1.5		0.0	1.5	0.0
Earnings related to transition service agreements						0.1		0.0	0.1	0.0
Segment Reconciling Items
Business Acquisition [Line Items]
Acquisition and integration costs						95.4		19.4	131.9	25.1
Interest and other financing items						(44.0)		(13.6)	(59.8)	(27.0)
Cost of products sold
Business Acquisition [Line Items]
Inventory adjustment									27.2
Acquisition and integration costs						31.7			27.2
Selling, General and Administrative Expenses
Business Acquisition [Line Items]
Acquisition and integration costs									131.9	25.1
Selling, General and Administrative Expenses | Segment Reconciling Items
Business Acquisition [Line Items]
Acquisition and integration costs						29.1		(16.5)	48.0	22.2
Interest Expense
Business Acquisition [Line Items]
Interest and other financing items						33.2		$ 2.9	65.6	$ 2.9
Other Items, Net
Business Acquisition [Line Items]
Business Combination, Separately Recognized Transactions, Net Gains and Losses									(9.0)
Spectrum Brands Holdings
Business Acquisition [Line Items]
Payments to acquire business		$ 2,000.0
Initial cash paid including estimated working capital adjustments		1,956.2
Cash consideration initially allocated to divested business		$ 450.0
Success fees											$ 6.0	$ 2.0	$ 13.0
Inventory adjustment									14.2
Inventory fair value adjustment						11.2			11.2
Net sales									99.9
Earnings before income taxes									(1.1)
Spectrum Brands Holdings | Other Items, Net
Business Acquisition [Line Items]
Interest and other financing items									(5.8)
Spectrum Auto Care Acquisition
Business Acquisition [Line Items]
Payments to acquire business			$ 937.5
Initial cash paid including estimated working capital adjustments	$ 938.7
Inventory adjustment						19.5
Acquisition purchase price			1,250.0
Newly-issued common stock in acquisition	$ 5.3		$ 312.5
Newly-issued common stock in acquisition (in shares)	5,278,921
Fair value of equity consideration	$ 240.5
Opening stock price (in dollars per share)	$ 45.55
Additional consideration (in dollars per share)	$ 36,800,000
Net sales									84.5
Earnings before income taxes									(0.8)
Spectrum Auto Care Acquisition | Scenario, Forecast
Business Acquisition [Line Items]
Inventory adjustment					$ 6.5
Spectrum Auto Care Acquisition | Pro Forma
Business Acquisition [Line Items]
Restructuring charges						3.1			7.1
Spectrum Auto Care Acquisition | Cost of products sold
Business Acquisition [Line Items]
Inventory adjustment									13.0
Spectrum Auto Care Acquisition | Cost of products sold | Scenario, Forecast
Business Acquisition [Line Items]
Inventory adjustment					$ 5.1
Nu Finish Acquisition
Business Acquisition [Line Items]
Inventory adjustment							$ 0.2
Acquisition purchase price				$ 38.1
Net sales						$ 1.9			2.9
Earnings before income taxes									$ 0.8
Other intangible assets, net				$ 21.8