Fair Value of Assets and Liabilities (Details 3) (USD $) In Millions, unless otherwise specified	12 Months Ended			3 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Mar. 31, 2014	Dec. 31, 2011
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation Calculation Rollforward
Balance at beginning of period	$ 2,186	$ 3,042	$ 3,095	$ 2,186
Total gains (losses) included in: net income	44	20	27
Total gains (losses) included in: OCI	(8)	47	223
Transfers into Level 3	147	136	491
Transfers out of Level 3	(294)	(485)	(253)
Sold in LBL disposition	(347)
Purchases			703
Purchases/Issues	327	754
Sales	(400)	(1,108)	(1,056)
Settlements	(186)	(220)	(188)
Balance at end of period	1,469	2,186	3,042
Fair value assets and liabilities measured on recurring basis, gain (loss) included in earnings
Total realized and unrealized gains (losses) included in net income, recurring Level 3 assets and liabilities	53	129	195
Free-standing derivatives, assets	2	9	3
Free-standing derivatives, liabilities	9	14	30
Assets transferred between Level 1 and Level 2	0	0
Liabilities transferred between Level 1 and Level 2	0	0
Realized capital gains and losses
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation Calculation Rollforward
Total gains (losses) included in: net income	34	3
Net investment income
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation Calculation Rollforward
Total gains (losses) included in: net income	13	18	27
Interest credited to contractholder funds
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation Calculation Rollforward
Total gains (losses) included in: net income	(5)	40	132
Life and annuity contract benefits
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation Calculation Rollforward
Total gains (losses) included in: net income	15	74	36
Loss on disposition of operations
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation Calculation Rollforward
Total gains (losses) included in: net income	(4)	(6)
Fixed income securities
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation Calculation Rollforward
Balance at beginning of period	1,697	2,897	3,146	1,697
Total gains (losses) included in: net income	22	1	7
Total gains (losses) included in: OCI	6	46	214
Transfers into Level 3	143	123	491
Transfers out of Level 3	(290)	(472)	(253)
Sold in LBL disposition	4
Transfer from held for sale		(385)
Purchases			512
Purchases/Issues	197	744
Sales	(216)	(1,048)	(1,018)
Settlements	(176)	(209)	(202)
Balance at end of period	1,387	1,697	2,897
U.S. government and agencies
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation Calculation Rollforward
Balance at beginning of period	7	8		7
Transfers into Level 3			8
Settlements	(1)	(1)
Balance at end of period	6	7	8
Municipal
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation Calculation Rollforward
Balance at beginning of period	343	965	1,332	343
Total gains (losses) included in: net income	(2)	(33)	(35)
Total gains (losses) included in: OCI	18	47	76
Transfers into Level 3		6	53
Transfers out of Level 3	(17)	(63)	(28)
Transfer from held for sale		(51)
Purchases			46
Purchases/Issues	6	55
Sales	(74)	(558)	(463)
Settlements	(4)	(25)	(16)
Balance at end of period	270	343	965
Corporate
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation Calculation Rollforward
Balance at beginning of period	1,109	1,617	1,405	1,109
Total gains (losses) included in: net income	24	35	20
Total gains (losses) included in: OCI	(14)	(32)	68
Transfers into Level 3	89	84	387
Transfers out of Level 3	(125)	(323)	(92)
Transfer from held for sale		(244)
Purchases			276
Purchases/Issues	64	504
Sales	(140)	(389)	(310)
Settlements	(116)	(143)	(137)
Balance at end of period	891	1,109	1,617
Asset-backed securities ("ABS")
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation Calculation Rollforward
Balance at beginning of period	192	251	297	192
Total gains (losses) included in: net income	1		26
Total gains (losses) included in: OCI	2	29	61
Transfers into Level 3	49	29	43
Transfers out of Level 3	(144)	(86)	(81)
Transfer from held for sale		(85)
Purchases			155
Purchases/Issues	119	174
Sales		(82)	(217)
Settlements	(23)	(38)	(33)
Balance at end of period	196	192	251
Residential mortgage-backed securities ("RMBS")
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation Calculation Rollforward
Balance at beginning of period	2	3	51	2
Transfers out of Level 3			(47)
Settlements	(1)	(1)	(1)
Balance at end of period	1	2	3
Commercial mortgage-backed securities ("CMBS")
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation Calculation Rollforward
Balance at beginning of period	43	52	60	43
Total gains (losses) included in: net income	(1)	(1)	(4)
Total gains (losses) included in: OCI		2	9
Transfers into Level 3	5	4
Transfers out of Level 3	(4)		(5)
Sold in LBL disposition	4
Transfer from held for sale		(5)
Purchases			34
Purchases/Issues	8	11
Sales	(1)	(19)	(27)
Settlements	(31)	(1)	(15)
Balance at end of period	23	43	52
Commercial mortgage-backed securities ("CMBS") | LBL
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation Calculation Rollforward
Transfer from held for sale				4
Redeemable preferred stock
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation Calculation Rollforward
Balance at beginning of period	1		1	1
Purchases			1
Sales	(1)		(1)
Balance at end of period			1
Equity securities
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation Calculation Rollforward
Balance at beginning of period	132	171	43	132
Total gains (losses) included in: net income	22	3	(7)
Total gains (losses) included in: OCI	(16)	7	9
Transfers out of Level 3	(2)
Purchases			164
Purchases/Issues	83	1
Sales	(136)	(50)	(38)
Balance at end of period	83	132	171
Short-term investments
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation Calculation Rollforward
Purchases/Issues	45
Sales	(40)
Balance at end of period	5
Free-standing derivatives, net
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation Calculation Rollforward
Balance at beginning of period	(5)	(27)	(95)	(5)
Total gains (losses) included in: net income		19	27
Purchases			27
Purchases/Issues	2	9
Settlements	(4)	(6)	14
Balance at end of period	(7)	(5)	(27)
Other assets
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation Calculation Rollforward
Balance at beginning of period		1			1
Total gains (losses) included in: net income	1	(1)
Balance at end of period	1				1
Assets held for sale
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation Calculation Rollforward
Balance at beginning of period	362			362
Total gains (losses) included in: net income	(1)	(2)
Total gains (losses) included in: OCI	2	(6)
Transfers into Level 3	4	13
Transfers out of Level 3	(2)	(13)
Sold in LBL disposition	(351)
Transfer from held for sale		385
Sales	(8)	(10)
Settlements	(6)	(5)
Balance at end of period		362
Assets held for sale | LBL
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation Calculation Rollforward
Transfer from held for sale				$ (4)