Stock Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Sep. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Document Period End Date			Jun. 30, 2017
Stock-based compensation	$ 6.0	$ 18.4	$ 33.0	$ 58.4
HGI [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period			343
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized	$ 1.6		$ 1.6
Unrecognized compensation cost expected to recognized, years			1 year 2 months 29 days
Granted			$ 2,300,000
Exercised/Released			$ 29,800,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value			$ 2.9
Employee Service Share-based Compensation, Cash Received from Exercise of Stock Options			$ 5.5
HGI [Member] | Stock option awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average remaining contractual term of outstanding stock option awards			4 years 5 months 35 days
HGI [Member] | Restricted stock awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercised/Released			1,832
Exercised/Released			$ 12.69
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	168		168		1,975
HGI [Member] | Restricted stock units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercised/Released			42
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period			0
Stock Issued During Period, Shares, Restricted Stock Award, Gross			0
Granted			$ 0.00
Exercised/Released			12.33
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number					42
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Weighted Average Grant Date Fair Value			$ 0
HGI [Member] | Time Based Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period			25
Granted			$ 15.71
Exercised/Released			$ 400,000
HGI [Member] | Warrant [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Number of Shares			600
Exercised			$ 13.13
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Weighted Average Grant Date Fair Value			$ 3.22
HGI [Member] | Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term			0.00%	0.00%
Options, granted			318
Exercised/Released			$ 1,900,000
Stock options vested and exercisable at June 30, 2017			3,618
Exercised			$ 11.12
Spectrum Brands [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Issued During Period, Shares, Restricted Stock Award, Gross			293
Granted			$ 39,000,000
Exercised/Released			49,000,000
Spectrum Brands [Member] | Restricted stock awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted			$ 133.15
Spectrum Brands [Member] | Restricted stock units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercised/Released			499
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period			693
Stock Issued During Period, Shares, Restricted Stock Award, Gross			293
Stock Issued During Period, Value, Restricted Stock Award, Gross			$ 88.0
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized	$ 25.3		$ 25.3
Granted			$ 127.02
Exercised/Released			$ 109.03
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	763		763		577
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Weighted Average Grant Date Fair Value			$ 39,000,000
Spectrum Brands [Member] | Time Based Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period			0
Granted			$ 0.00
Exercised/Released			$ 0
Spectrum Brands [Member] | Performance-based and Time-based Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Issued During Period, Shares, Restricted Stock Award, Gross			400
Granted			$ 122.53
Spectrum Brands [Member] | Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options, granted			0
Exercised/Released			$ 0
Restricted stock awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	146		593
Stock option awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	1,900		1,781
Employee Stock Option [Member] | HGI [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate			1.79542%	1.6545%
Volatility			5 years	5 years
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate			35.11387%	37.40%
Employee Stock Option [Member] | HGI [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate			2.24703%	1.7425%
Volatility			6 years 6 months	5 years 6 months
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate			37.54231%	37.90%
Share-based Compensation Award, Tranche One [Member] | Spectrum Brands [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercised/Released			$ 100,000
Share-based Compensation Award, Tranche One [Member] | Spectrum Brands [Member] | Restricted stock awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted			$ 140.38
Share-based Compensation Award, Tranche One [Member] | Spectrum Brands [Member] | Performance-based and Time-based Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Issued During Period, Shares, Restricted Stock Award, Gross			1
Share-based Compensation Award, Tranche Two [Member] | Spectrum Brands [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercised/Released			$ 12,900,000
Share-based Compensation Award, Tranche Two [Member] | Spectrum Brands [Member] | Restricted stock awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted			$ 122.66
Share-based Compensation Award, Tranche Two [Member] | Spectrum Brands [Member] | Performance-based and Time-based Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Issued During Period, Shares, Restricted Stock Award, Gross			105
Share-based Compensation Award, Tranche Three [Member] | Spectrum Brands [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercised/Released			$ 36,000,000
Share-based Compensation Award, Tranche Three [Member] | Spectrum Brands [Member] | Restricted stock awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted			$ 122.43
Share-based Compensation Award, Tranche Three [Member] | Spectrum Brands [Member] | Performance-based and Time-based Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Issued During Period, Shares, Restricted Stock Award, Gross			294
Severance Cost, Future Bonus [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Severance Costs			$ 3.0