Goodwill and Intangibles, including DAC and VOBA - Summary of Definite Lived Intangible Assets (Detail) (USD $) In Millions, unless otherwise specified			9 Months Ended			9 Months Ended			9 Months Ended			9 Months Ended
Jun. 30, 2013	Sep. 30, 2012	Jun. 30, 2013 Minimum [Member]	Jun. 30, 2013 Maximum [Member]	Jun. 30, 2013 Customer relationships [Member]	Sep. 30, 2012 Customer relationships [Member]	Jun. 30, 2013 Customer relationships [Member] Minimum [Member]	Jun. 30, 2013 Customer relationships [Member] Maximum [Member]	Jun. 30, 2013 Trade names [Member]	Sep. 30, 2012 Trade names [Member]	Jun. 30, 2013 Trade names [Member] Minimum [Member]	Jun. 30, 2013 Trade names [Member] Maximum [Member]	Jun. 30, 2013 Technology assets [Member]	Sep. 30, 2012 Technology assets [Member]	Jun. 30, 2013 Technology assets [Member] Minimum [Member]	Jun. 30, 2013 Technology assets [Member] Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Cost	$ 1,226.4	$ 1,038.0			$ 879.4	$ 796.2			$ 171.5	$ 150.8			$ 175.5	$ 91.0
Accumulated Amortization	(223.9)	(164.1)			(147.9)	(113.0)			(41.2)	(28.3)			(34.8)	(22.8)
Net	$ 1,002.5	$ 873.9			$ 731.5	$ 683.2			$ 130.3	$ 122.5			$ 140.7	$ 68.2
Amortizable Life			1 year	20 years			15 years	20 years			1 year	12 years			4 years	17 years

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275

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- Definition

Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

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- Definition

Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

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- Definition

Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

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