Goodwill and Intangibles, including DAC and VOBA - Summary of Amortization Expense of Definite Lived Intangible Assets (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2013	Apr. 01, 2012	Mar. 31, 2013	Apr. 01, 2012
Finite-Lived Intangible Assets [Line Items]
Amortization of Intangible Assets	$ 49.0	$ 58.8	$ 135.6	$ 115.5
Customer relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization of Intangible Assets	11.3	10.3	21.7	19.9
Trade names [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization of Intangible Assets	4.3	3.1	7.9	6.2
Technology assets [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization of Intangible Assets	4.5	2.4	7.6	4.3
Definite Lived Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization of Intangible Assets	$ 20.1	$ 15.8	$ 37.2	$ 30.4