Fair Value of Financial Instruments - Additional Information (Detail) (USD $)	3 Months Ended
	Dec. 31, 2013		Dec. 31, 2012
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
Net transfer In (Out) of Level 3 (a)		[1]	$ (14,100,000)	[2]

[1] {F|ahBzfndlYmZpbGluZ3MtaHJkcmoLEgZYTUxEb2MiXlhCUkxEb2NHZW5JbmZvOjkzMWUzNTc5OTc5ZDQ0NDA5NDZlZDlmNTcyN2JmYzMyfFRleHRTZWxlY3Rpb246REVBMUNFNjUwNzU2Q0U3MUVERDcwNjlDQTlGMzA0OTIM}

[2] (a)The net transfers in and out of Level 3 during the three months ended December 30, 2012 was exclusively to or from Level 2.