Fair Value Measurements (Details 3) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012		Sep. 30, 2011
Fixed Maturities [Member] | Asset-backed Securities [Member]
Roll Forward of Financial Instruments (Assets) Measured at Fair Value on Recurring Basis Using Significant Unobservable Inputs (Level 3)
Fair value, Beginning Balance	$ 238		$ 317		$ 259
Total realized/unrealized gains (losses) included in net income	(3)	[1],[2],[3]	0	[1],[2],[3]
Total realized/unrealized gains (losses) included in OCI	22	[4]	9	[4]
Purchases	14		0
Settlements	(3)		(34)
Sales	(34)		(9)
Transfers into Level 3	0	[5]	0	[5]
Transfers out of Level 3	(9)	[5]	(24)	[5]
Fair value, Ending Balance	225				259
Changes in unrealized gains (losses) included in net income related to financial instruments still held at March 31, 2011	(4)	[3],[6]	0	[3],[6]
Fixed Maturities [Member] | Available-for-sale Securities [Member]
Roll Forward of Financial Instruments (Assets) Measured at Fair Value on Recurring Basis Using Significant Unobservable Inputs (Level 3)
Fair value, Beginning Balance	4,169		3,842		4,450
Total realized/unrealized gains (losses) included in net income	30	[1],[2],[3]	(4)	[1],[2],[3]
Total realized/unrealized gains (losses) included in OCI	78	[4]	102	[4]
Purchases	56		334
Settlements	(129)		(112)
Sales	(771)		(64)
Transfers into Level 3	100	[5]	736	[5]
Transfers out of Level 3	(24)	[5]	(384)	[5]
Fair value, Ending Balance	3,509				4,450
Changes in unrealized gains (losses) included in net income related to financial instruments still held at March 31, 2011	(8)	[3],[6]	(10)	[3],[6]
Fixed Maturities [Member] | Residential Mortgage Backed Securities [Member]
Roll Forward of Financial Instruments (Assets) Measured at Fair Value on Recurring Basis Using Significant Unobservable Inputs (Level 3)
Fair value, Beginning Balance	1,133		933		975
Total realized/unrealized gains (losses) included in net income	29	[1],[2],[3]	2	[1],[2],[3]
Total realized/unrealized gains (losses) included in OCI	15	[4]	29	[4]
Purchases	13		61
Settlements	(32)		(28)
Sales	(192)		(22)
Transfers into Level 3	0	[5]	0	[5]
Transfers out of Level 3	0	[5]	0	[5]
Fair value, Ending Balance	966				975
Changes in unrealized gains (losses) included in net income related to financial instruments still held at March 31, 2011	0	[3],[6]	(5)	[3],[6]
Fixed Maturities [Member] | US States and Political Subdivisions Debt Securities [Member]
Roll Forward of Financial Instruments (Assets) Measured at Fair Value on Recurring Basis Using Significant Unobservable Inputs (Level 3)
Fair value, Beginning Balance	169		382		521
Total realized/unrealized gains (losses) included in net income	0	[1],[2],[3]	0	[1],[2],[3]
Total realized/unrealized gains (losses) included in OCI	1	[4]	(12)	[4]
Purchases	0		151
Settlements	0		0
Sales	(38)		0
Transfers into Level 3	0	[5]	0	[5]
Transfers out of Level 3	0	[5]	0	[5]
Fair value, Ending Balance	132				521
Changes in unrealized gains (losses) included in net income related to financial instruments still held at March 31, 2011	0	[3],[6]	0	[3],[6]
Fixed Maturities [Member] | Foreign Government Debt Securities [Member]
Roll Forward of Financial Instruments (Assets) Measured at Fair Value on Recurring Basis Using Significant Unobservable Inputs (Level 3)
Fair value, Beginning Balance	34		37		42
Total realized/unrealized gains (losses) included in net income	1	[1],[2],[3]	0	[1],[2],[3]
Total realized/unrealized gains (losses) included in OCI	(1)	[4]	0	[4]
Purchases	10		6
Settlements	(1)		(1)
Sales	(6)		0
Transfers into Level 3	0	[5]	0	[5]
Transfers out of Level 3	(2)	[5]	0	[5]
Fair value, Ending Balance	35				42
Changes in unrealized gains (losses) included in net income related to financial instruments still held at March 31, 2011	0	[3],[6]	0	[3],[6]
Fixed Maturities [Member] | Corporate Debt Securities [Member]
Roll Forward of Financial Instruments (Assets) Measured at Fair Value on Recurring Basis Using Significant Unobservable Inputs (Level 3)
Fair value, Beginning Balance	1,340		1,497		1,348
Total realized/unrealized gains (losses) included in net income	16	[1],[2],[3]	(3)	[1],[2],[3]
Total realized/unrealized gains (losses) included in OCI	(8)	[4]	9	[4]
Purchases	18		106
Settlements	(58)		(19)
Sales	(255)		(32)
Transfers into Level 3	56	[5]	139	[5]
Transfers out of Level 3	(13)	[5]	(349)	[5]
Fair value, Ending Balance	1,096				1,348
Changes in unrealized gains (losses) included in net income related to financial instruments still held at March 31, 2011	(2)	[3],[6]	(1)	[3],[6]
Fixed Maturities [Member] | Commercial Mortgage Backed Securities [Member]
Roll Forward of Financial Instruments (Assets) Measured at Fair Value on Recurring Basis Using Significant Unobservable Inputs (Level 3)
Fair value, Beginning Balance	532		348		620
Total realized/unrealized gains (losses) included in net income	(2)	[1],[2],[3]	(4)	[1],[2],[3]
Total realized/unrealized gains (losses) included in OCI	13	[4]	18	[4]
Purchases	0		10
Settlements	(14)		(21)
Sales	(60)		0
Transfers into Level 3	21	[5]	280	[5]
Transfers out of Level 3	0	[5]	(11)	[5]
Fair value, Ending Balance	490				620
Changes in unrealized gains (losses) included in net income related to financial instruments still held at March 31, 2011	(2)	[3],[6]	(4)	[3],[6]
Fixed Maturities [Member] | Collateralized Debt Obligations [Member]
Roll Forward of Financial Instruments (Assets) Measured at Fair Value on Recurring Basis Using Significant Unobservable Inputs (Level 3)
Fair value, Beginning Balance	723		328		685
Total realized/unrealized gains (losses) included in net income	(11)	[1],[2],[3]	1	[1],[2],[3]
Total realized/unrealized gains (losses) included in OCI	36	[4]	49	[4]
Purchases	1		0
Settlements	(21)		(9)
Sales	(186)		(1)
Transfers into Level 3	23	[5]	317	[5]
Transfers out of Level 3	0	[5]	0	[5]
Fair value, Ending Balance	565				685
Changes in unrealized gains (losses) included in net income related to financial instruments still held at March 31, 2011	0	[3],[6]	0	[3],[6]
Fixed Maturities, FVO [Member]
Roll Forward of Financial Instruments (Assets) Measured at Fair Value on Recurring Basis Using Significant Unobservable Inputs (Level 3)
Fair value, Beginning Balance	199		484		497
Total realized/unrealized gains (losses) included in net income	14	[1],[2],[3]	27	[1],[2],[3]
Total realized/unrealized gains (losses) included in OCI	0	[4]	0	[4]
Purchases	6		0
Settlements	(1)		0
Sales	(18)		(14)
Transfers into Level 3	2	[5]	0	[5]
Transfers out of Level 3	(1)	[5]	0	[5]
Fair value, Ending Balance	201				497
Changes in unrealized gains (losses) included in net income related to financial instruments still held at March 31, 2011	$ 35	[3],[6]	$ 16	[3],[6]

[1] Includes fair value of reinsurance recoverables of approximately $435 and $1.6 billion as of March 31, 2013 and 2012, respectively, related to a transaction entered into with an affiliated captive reinsurer. See Note 11 - Transactions with Affiliates of Notes to Condensed Consolidated Financial Statements for more information.

[2] The Company classifies gains and losses on GMWB reinsurance derivatives and Guaranteed Living Benefit embedded derivatives as unrealized gains (losses) for purposes of disclosure in this table because it is impracticable to track on a contract-by-contract basis the realized gains (losses) for these derivatives and embedded derivatives.

[3] All amounts in these rows are reported in net realized capital gains (losses). The realized/unrealized gains (losses) included in net income for separate account assets are offset by an equal amount for separate account liabilities, which results in a net zero impact on net income for the Company. All amounts are before income taxes and amortization of DAC.

[4] All amounts are before income taxes and amortization of DAC.

[5] Transfers in and/or (out) of Level 3 are primarily attributable to the availability of market observable information and the re-evaluation of the observability of pricing inputs.

[6] Includes both market and non-market impacts in deriving realized and unrealized gains (losses).