Goodwill and Intangibles, including DAC and VOBA, net - Additional Information (Detail) (USD $) In Millions, except Share data in Thousands, unless otherwise specified	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Finite-Lived Intangible Assets [Line Items]
Intangible assets amortization method	straight-line method
Goodwill, Acquired During Period	$ 65.8	$ 786.6
Amortization of intangibles	179.2	260.1	224.3
Finite-Lived Intangible Assets, Accumulated Amortization	323.2	244.5
2014	77.5
2015	78.5
2016	78.5
2017	78.5
2018	78.5
VOBA
Finite-Lived Intangible Assets [Line Items]
Cumulative adjustments for net unrealized investment gains	(164.2)	(81.4)
Amortization of intangibles	55.8	137.0	145.5
Finite-Lived Intangible Assets, Accumulated Amortization	338.4	270.5
2014	42.8
2015	38.4
2016	31.2
2017	25.0
2018	25.5
DAC
Finite-Lived Intangible Assets [Line Items]
Cumulative adjustments for net unrealized investment gains	(55.5)	18.6
Amortization of intangibles	41.7	45.3	15.2
Deferred sales inducements, net of shadow adjustments	32.7	26.2
Minimum
Finite-Lived Intangible Assets [Line Items]
Amortization period, intangible asset	1 year
Accretion Rate, VOBA	4.00%
Maximum
Finite-Lived Intangible Assets [Line Items]
Amortization period, intangible asset	20 years
Accretion Rate, VOBA	5.00%
Weighted average | VOBA
Finite-Lived Intangible Assets [Line Items]
Amortization period, intangible asset	4 years 9 months 18 days
Hardware Acquisition
Finite-Lived Intangible Assets [Line Items]
Goodwill, Acquired During Period	$ 0
Russel Hobbs 2007 Plan [Member] | Maximum
Finite-Lived Intangible Assets [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	1,000
Employee Stock Option | HGI's executive bonus plan
Finite-Lived Intangible Assets [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	1,100
Compass | Compass Incentive Plan
Finite-Lived Intangible Assets [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	647
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	1,000