Derivative Financial Instruments - Summary of Gain (Loss) Recognized in Income on Derivatives (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	$ (2.8)
Foreign exchange contracts | Other (expense) income, net
Derivative Instruments, Gain (Loss) [Line Items]
Gain Recognized in Income on Derivatives	(2.4)	$ 1.2	$ (2.7)	$ 3.3
Spectrum Brands [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	(18.4)	(10.4)	(19.2)	32.8
Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net	0.6	0.0	0.6	0.0
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	(0.2)	0.2	0.4	0.3
Spectrum Brands [Member] | Discontinued Operations [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net		3.6	(6.1)	8.3
Spectrum Brands [Member] | Interest Rate Swap [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	1.8	(0.4)	3.8	(0.3)
Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net	0.6	0.0	0.6	0.0
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	0.0	0.0	0.0	0.0
Spectrum Brands [Member] | Interest Rate Swap [Member] | Discontinued Operations [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	0.7	(0.7)	0.3	(1.0)
Spectrum Brands [Member] | Commodity contracts | Consumer products cost of goods sold classification
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	(0.6)	3.7	1.2	3.8
Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net	0.0	0.0	0.0	0.0
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	0.3	0.3	0.6	0.3
Spectrum Brands [Member] | Commodity contracts | Discontinued Operations [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	1.3	1.4	2.5	2.2
Spectrum Brands [Member] | Net Investment Hedging [Member] | Discontinued Operations [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	0.0	0.0	0.0	0.0
Spectrum Brands [Member] | Net Investment Hedging [Member] | Other (expense) income, net
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	(15.2)	(9.2)	(21.8)	23.3
Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net	0.0	0.0	0.0	0.0
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	0.0	0.0	0.0	0.0
Spectrum Brands [Member] | Foreign exchange contracts | Consumer products cost of goods sold classification
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	(4.4)	(4.4)	(2.4)	5.9
Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net	0.0	0.0	0.0	0.0
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	(0.5)	(0.1)	(0.3)	0.0
Spectrum Brands [Member] | Foreign exchange contracts | Discontinued Operations [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	$ (4.8)	2.9	(8.9)	7.1
Spectrum Brands [Member] | Foreign exchange contracts | Sales Revenue, Net [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net		(0.1)	0.0	0.1
Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net		0.0	0.0	0.0
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net		$ 0.0	$ 0.1	$ 0.0