Fair Value of Assets and Liabilities (Details 3) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation Calculation Rollforward
Balance at beginning of period	$ 2,186	$ 1,469	$ 2,186	$ 3,042
Total gains (losses) included in: net income		5	44	20
Total gains (losses) included in: OCI		(28)	(8)	47
Transfers into Level 3		59	147	136
Transfers out of Level 3		(433)	(294)	(485)
Sold in LBL disposition			(347)	0
Purchases		276	327	754
Issues		0
Sales		(223)	(400)	(1,108)
Settlements		(152)	(186)	(220)
Balance at end of period		973	1,469	2,186
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		24	53	129
Other investments: Free-standing derivatives		1	2	9
Free-standing derivatives, liabilities		8	9	14
Assets transferred between Level 1 and Level 2			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		8	(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)	(13)	(18)
Interest credited to contractholder funds
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation Calculation Rollforward
Total gains (losses) included in: net income		(26)	5	(40)
Life and annuity contract benefits
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation Calculation Rollforward
Total gains (losses) included in: net income		7	(15)	(74)
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	1,387	1,697	2,897
Total gains (losses) included in: net income		7	22	1
Total gains (losses) included in: OCI		(23)	6	46
Transfers into Level 3		59	143	123
Transfers out of Level 3		(433)	(290)	(472)
Sold in LBL disposition			4	(385)
Purchases		172	197	744
Issues		0
Sales		(172)	(216)	(1,048)
Settlements		(151)	(176)	(209)
Balance at end of period		846	1,387	1,697
U.S. government and agencies
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation Calculation Rollforward
Balance at beginning of period	7	6	7	8
Total gains (losses) included in: net income		0	0	0
Total gains (losses) included in: OCI		0	0	0
Transfers into Level 3		0	0	0
Transfers out of Level 3		0	0	0
Sold in LBL disposition			0	0
Purchases		0	0	0
Issues		0
Sales		0	0	0
Settlements		(1)	(1)	(1)
Balance at end of period		5	6	7
Municipal
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation Calculation Rollforward
Balance at beginning of period	343	270	343	965
Total gains (losses) included in: net income		(4)	(2)	(33)
Total gains (losses) included in: OCI		(7)	18	47
Transfers into Level 3		3	0	6
Transfers out of Level 3		(2)	(17)	(63)
Sold in LBL disposition			0	(51)
Purchases		0	6	55
Issues		0
Sales		(91)	(74)	(558)
Settlements		(8)	(4)	(25)
Balance at end of period		161	270	343
Corporate - public
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation Calculation Rollforward
Balance at beginning of period		214
Total gains (losses) included in: net income		0
Total gains (losses) included in: OCI		0
Transfers into Level 3		0
Transfers out of Level 3		(175)
Purchases		11
Issues		0
Sales		0
Settlements		(4)
Balance at end of period		46	214
Corporate - privately placed
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation Calculation Rollforward
Balance at beginning of period		677
Total gains (losses) included in: net income		13
Total gains (losses) included in: OCI		(20)
Transfers into Level 3		13
Transfers out of Level 3		(106)
Purchases		79
Issues		0
Sales		(74)
Settlements		(80)
Balance at end of period		502	677
ABS - CDO
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation Calculation Rollforward
Balance at beginning of period		104
Total gains (losses) included in: net income		(1)
Total gains (losses) included in: OCI		4
Transfers into Level 3		43
Transfers out of Level 3		(52)
Purchases		0
Issues		0
Sales		(2)
Settlements		(35)
Balance at end of period		61	104
ABS - consumer and other
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation Calculation Rollforward
Balance at beginning of period		92
Total gains (losses) included in: net income		(1)
Total gains (losses) included in: OCI		0
Transfers into Level 3		0
Transfers out of Level 3		(98)
Purchases		70
Issues		0
Sales		(5)
Settlements		(8)
Balance at end of period		50	92
Corporate
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation Calculation Rollforward
Balance at beginning of period	1,109	891	1,109	1,617
Total gains (losses) included in: net income			24	35
Total gains (losses) included in: OCI			(14)	(32)
Transfers into Level 3			89	84
Transfers out of Level 3			(125)	(323)
Sold in LBL disposition			0	(244)
Purchases			64	504
Sales			(140)	(389)
Settlements			(116)	(143)
Balance at end of period			891	1,109
ABS
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation Calculation Rollforward
Balance at beginning of period	192	196	192	251
Total gains (losses) included in: net income			1	0
Total gains (losses) included in: OCI			2	29
Transfers into Level 3			49	29
Transfers out of Level 3			(144)	(86)
Sold in LBL disposition			0	(85)
Purchases			119	174
Sales			0	(82)
Settlements			(23)	(38)
Balance at end of period			196	192
RMBS
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation Calculation Rollforward
Balance at beginning of period	2	1	2	3
Total gains (losses) included in: net income		0	0	0
Total gains (losses) included in: OCI		0	0	0
Transfers into Level 3		0	0	0
Transfers out of Level 3		0	0	0
Sold in LBL disposition			0	0
Purchases		0	0	0
Issues		0
Sales		0	0	0
Settlements		0	(1)	(1)
Balance at end of period		1	1	2
CMBS
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation Calculation Rollforward
Balance at beginning of period	43	23	43	52
Total gains (losses) included in: net income		0	(1)	(1)
Total gains (losses) included in: OCI		0	0	2
Transfers into Level 3		0	5	4
Transfers out of Level 3		0	(4)	0
Sold in LBL disposition			4	(5)
Purchases		12	8	11
Issues		0
Sales		0	(1)	(19)
Settlements		(15)	(31)	(1)
Balance at end of period		20	23	43
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	0	1	1
Total gains (losses) included in: net income			0	0
Total gains (losses) included in: OCI			0	0
Transfers into Level 3			0	0
Transfers out of Level 3			0	0
Sold in LBL disposition			0	0
Purchases			0	0
Sales			(1)	0
Settlements			0	0
Balance at end of period			0	1
Equity securities
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation Calculation Rollforward
Balance at beginning of period	132	83	132	171
Total gains (losses) included in: net income		(3)	22	3
Total gains (losses) included in: OCI		(5)	(16)	7
Transfers into Level 3		0	0	0
Transfers out of Level 3		0	(2)	0
Sold in LBL disposition			0	0
Purchases		69	83	1
Issues		0
Sales		(11)	(136)	(50)
Settlements		0	0	0
Balance at end of period		133	83	132
Short-term investments
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation Calculation Rollforward
Balance at beginning of period	0	5	0
Total gains (losses) included in: net income		0	0
Total gains (losses) included in: OCI		0	0
Transfers into Level 3		0	0
Transfers out of Level 3		0	0
Sold in LBL disposition			0
Purchases		35	45
Issues		0
Sales		(40)	(40)
Settlements		0	0
Balance at end of period		0	5	0
Free-standing derivatives, net
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation Calculation Rollforward
Balance at beginning of period	(5)	(7)	(5)	(27)
Total gains (losses) included in: net income		1	0	19
Total gains (losses) included in: OCI		0	0	0
Transfers into Level 3		0	0	0
Transfers out of Level 3		0	0	0
Sold in LBL disposition			0	0
Purchases		0	2	9
Issues		0
Sales		0	0	0
Settlements		(1)	(4)	(6)
Balance at end of period		(7)	(7)	(5)
Other assets
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation Calculation Rollforward
Balance at beginning of period	0	1	0	1
Total gains (losses) included in: net income		0	1	(1)
Total gains (losses) included in: OCI		0	0	0
Transfers into Level 3		0	0	0
Transfers out of Level 3		0	0	0
Sold in LBL disposition			0	0
Purchases		0	0	0
Issues		0
Sales		0	0	0
Settlements		0	0	0
Balance at end of period		1	1	0
Assets held for sale
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation Calculation Rollforward
Balance at beginning of period	362	$ 0	362	0
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)	385
Purchases			0	0
Sales			(8)	(10)
Settlements			(6)	(5)
Balance at end of period			$ 0	$ 362
Assets held for sale | LBL
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation Calculation Rollforward
Transfer from held for sale	$ (4)