Investments - Reconciliation of Other than Temporary Impairment on Fixed Maturity (Detail) (USD $)	3 Months Ended	9 Months Ended		15 Months Ended
	Jun. 30, 2013	Jun. 30, 2013	Jul. 01, 2012	Jul. 01, 2013	Dec. 30, 2012	Jul. 31, 2012	Jan. 01, 2012
Investments, Debt and Equity Securities [Abstract]
Document Period End Date		Jun. 30, 2013
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Additions, Additional Credit Losses	$ 0	$ 0	$ 100,000	$ 100,000
Balance at the beginning of the period		2,700,000	700,000		2,700,000	2,700,000	2,600,000
Increases attributable to credit losses on securities:
Other-than-temporary impairment was not previously recognized	0	0	1,900,000	0
Balance at the end of the period	$ 2,700,000	$ 2,700,000			$ 2,700,000	$ 2,700,000	$ 2,600,000