Fair Value of Financial Instruments - Changes in Fair Value of Financial Instruments (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
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Document Period End Date			Jun. 30, 2013
Fair Value, Assets, Level 1 to Level 2 Transfers, Amount										$ 0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at Beginning of Period			206,000,000		546,500,000				419,000,000	1,011,800,000	684,100,000
Total Gains (Losses) Included in Earnings			(300,000)		41,100,000		100,000
Total Gains (Losses) Included in AOCI	(10,800,000)		(9,600,000)		1,200,000		(2,500,000)
Purchases	106,300,000		394,700,000		496,700,000		352,800,000
Sales			(9,600,000)		(24,900,000)		(8,200,000)
Settlements	(11,800,000)		(25,500,000)		(77,400,000)		(44,800,000)
Net transfer In (Out) of Level 3 (a)		[1]	(53,000,000)	[1]	28,600,000	[2]	30,300,000	[2]
Balance at End of Period	502,700,000		502,700,000						419,000,000	1,011,800,000	684,100,000
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at Beginning of Period			1,782,800,000		1,472,100,000				1,842,300,000	1,685,800,000	1,571,000,000
Total Gains (Losses) Included in Earnings	(106,300,000)		(46,800,000)		213,700,000		114,800,000
Total Gains (Losses) Included in AOCI
Purchases
Sales
Settlements	(2,800,000)		(2,800,000)
Net transfer In (Out) of Level 3		[1]		[1]		[2]		[2]
Balance at End of Period	1,733,200,000		1,733,200,000						1,842,300,000	1,685,800,000	1,571,000,000
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3			0		30,900,000	[2]
FIA embedded derivatives, included in contractholder funds [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at Beginning of Period			1,550,800,000		1,396,300,000				1,639,600,000	1,486,400,000	1,496,700,000
Total Gains (Losses) Included in Earnings	(53,700,000)		35,100,000		90,100,000		(10,300,000)
Total Gains (Losses) Included in AOCI
Purchases
Sales
Settlements
Net transfer In (Out) of Level 3		[1]		[1]		[2]		[2]
Balance at End of Period	1,585,900,000		1,585,900,000						1,639,600,000	1,486,400,000	1,496,700,000
Equity conversion feature of preferred stock [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at Beginning of Period			232,000,000		75,400,000				202,700,000	199,400,000	73,900,000
Total Gains (Losses) Included in Earnings	(52,600,000)		(81,900,000)		124,000,000		125,500,000
Total Gains (Losses) Included in AOCI
Purchases
Sales
Settlements	(2,800,000)		(2,800,000)
Net transfer In (Out) of Level 3		[1]		[1]		[2]		[2]
Balance at End of Period	147,300,000		147,300,000						202,700,000	199,400,000	73,900,000
Available-for-sale embedded derivatives [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at Beginning of Period					400,000						400,000
Total Gains (Losses) Included in Earnings					(400,000)		(400,000)
Total Gains (Losses) Included in AOCI
Purchases
Sales
Settlements
Net transfer In (Out) of Level 3						[2]		[2]
Balance at End of Period											400,000
US Treasury and Government [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value, Assets, Level 1 to Level 2 Transfers, Amount	79,300,000		79,300,000
Asset-backed and Hybrid Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3			53,000,000
Commercial mortgage-backed securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at Beginning of Period			5,000,000						6,200,000
Total Gains (Losses) Included in Earnings
Total Gains (Losses) Included in AOCI	(300,000)		(100,000)
Purchases			1,000,000
Sales
Settlements			0
Net transfer In (Out) of Level 3 (a)		[1]		[1]
Balance at End of Period	5,900,000		5,900,000						6,200,000
Corporates [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at Beginning of Period			135,300,000		159,700,000				356,500,000	205,800,000	120,100,000
Total Gains (Losses) Included in Earnings			(300,000)		200,000		200,000
Total Gains (Losses) Included in AOCI	(12,000,000)		(10,800,000)		(5,900,000)		(3,600,000)
Purchases	106,200,000		383,600,000		91,600,000		90,300,000
Sales			(9,600,000)		(24,400,000)		(7,700,000)
Settlements	(11,700,000)		(25,400,000)		(45,300,000)		(33,700,000)
Net transfer In (Out) of Level 3 (a)		[1]	(33,800,000)	[1]	29,900,000	[2]	40,200,000	[2]
Balance at End of Period	439,000,000		439,000,000						356,500,000	205,800,000	120,100,000
Hybrids [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at Beginning of Period			8,800,000		5,200,000					5,200,000	5,100,000
Total Gains (Losses) Included in Earnings
Total Gains (Losses) Included in AOCI			(100,000)				100,000
Purchases
Sales
Settlements
Net transfer In (Out) of Level 3 (a)			(8,700,000)	[1]		[2]		[2]
Balance at End of Period										5,200,000	5,100,000
Municipals [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at Beginning of Period										100,000	10,400,000
Total Gains (Losses) Included in Earnings
Total Gains (Losses) Included in AOCI					100,000
Purchases					10,200,000
Sales
Settlements
Net transfer In (Out) of Level 3 (a)					(10,200,000)	[2]	(10,300,000)	[2]
Balance at End of Period										100,000	10,400,000
Agency residential mortgage-backed securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at Beginning of Period					3,300,000						3,300,000
Total Gains (Losses) Included in Earnings
Total Gains (Losses) Included in AOCI
Purchases
Sales
Settlements
Net transfer In (Out) of Level 3 (a)					(3,300,000)	[2]	(3,300,000)	[2]
Balance at End of Period											3,300,000
Non-agency residential mortgage-backed securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at Beginning of Period					3,800,000					600,000	1,200,000
Total Gains (Losses) Included in Earnings					(100,000)		(100,000)
Total Gains (Losses) Included in AOCI							100,000
Purchases
Sales					(500,000)		(500,000)
Settlements					(300,000)		(100,000)
Net transfer In (Out) of Level 3 (a)					(2,300,000)	[2]		[2]
Balance at End of Period										600,000	1,200,000
Equity securities available-for-sale [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at Beginning of Period			0						10,000,000
Total Gains (Losses) Included in Earnings	0		0
Total Gains (Losses) Included in AOCI	1,600,000		1,600,000
Purchases	100,000		10,100,000
Sales	0		0
Settlements	0		0
Net transfer In (Out) of Level 3 (a)	0		0
Balance at End of Period	11,700,000		11,700,000						10,000,000
Corporate and Non-Agency Residential Mortgage-Backed Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3	(13,600,000)		(15,800,000)
Contingent purchase price reduction receivable [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at Beginning of Period			41,000,000						41,000,000	41,000,000	41,000,000
Total Gains (Losses) Included in Earnings					41,000,000
Total Gains (Losses) Included in AOCI
Purchases
Sales
Settlements
Net transfer In (Out) of Level 3 (a)		[1]		[1]		[2]		[2]
Balance at End of Period	41,000,000		41,000,000						41,000,000	41,000,000	41,000,000
Asset-backed securities [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3					$ 44,400,000	[2]	$ 43,900,000	[2]

[1] The net transfers in and out of Level 3 during the three and nine months ended June 30, 2013 were exclusively to or from Level 2.

[2] 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.