Fair Value of Financial Instruments - Additional Information (Detail) (USD $)	9 Months Ended				9 Months Ended	3 Months Ended	9 Months Ended
	Jun. 30, 2013	Jul. 01, 2012		Jul. 31, 2012	Jun. 30, 2013 Asset-backed and Hybrid Securities [Member]	Jun. 30, 2013 Corporate and Non-Agency Residential Mortgage-Backed Securities [Member]	Jun. 30, 2013 Corporate and Non-Agency Residential Mortgage-Backed Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Percentage of male contractholder	50.00%
Percentage of female contractholder	50.00%
Fair Value, Assets, Level 1 to Level 2 Transfers, Amount				$ 0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3					53,000,000	(13,600,000)	(15,800,000)
Transfers, assets, level 2 to 1	0			0
Transfers, liabilities, level 1 to 2	0			0
Transfers, liabilities, level 2 to 1	0			0
Net transfer level 3	$ 0	$ 30,900,000	[1]

[1] The net transfers in and out of Level 3 during the three and nine months ended July 1, 2012 was exclusively to or from Level 2.