Fair Value of Assets and Liabilities (Details 3) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation
Fair Value Measurement With Unobservable Inputs Reconciliation Liability Transfers To Held For Sale		$ 0
Fair Value Measurement with Unobservable Inputs Reconciliation Recurring Basis Sale of Assets of Disposal Group Including Discontinued Operations	347
Gains (losses) for Level 3 assets still held at the balance sheet date, included in earnings	17	12	18
Rollforward of Level 3 assets held at fair value on a recurring basis
Balance at beginning of period	1,604	2,041	1,965
Total gains (losses) included in: net income	20	33	60
Total gains (losses) included in: OCI	8	14	154
Transfers into Level 3	105	114	476
Transfers out of Level 3	(150)	(201)	(128)
Transfer to held for sale		0
Purchases/Issues	82	154	169
Sales	(135)	(382)	(508)
Issues			0
Settlements	(128)	(169)	(147)
Balance at end of period	1,059	1,604	2,041
Effect to net income reported in the Condensed Consolidated Statements of Operations and Comprehensive Income	20	33	60
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	29	142	228
Other investments: Free-standing derivatives	2	9	3
Assets transferred between Level 1 and Level 2	0	0	0
Liabilities transferred between Level 1 and Level 2	0	0	0
Realized capital gains and losses
Rollforward of Level 3 assets held at fair value on a recurring basis
Total gains (losses) included in: net income	11	20	38
Effect to net income reported in the Condensed Consolidated Statements of Operations and Comprehensive Income	11	20	38
Net investment income
Rollforward of Level 3 assets held at fair value on a recurring basis
Total gains (losses) included in: net income	12	14	22
Effect to net income reported in the Condensed Consolidated Statements of Operations and Comprehensive Income	12	14	22
Interest credited to contractholder funds
Rollforward of Level 3 assets held at fair value on a recurring basis
Total gains (losses) included in: net income	(5)	40	132
Effect to net income reported in the Condensed Consolidated Statements of Operations and Comprehensive Income	(5)	40	132
Contract benefits
Rollforward of Level 3 assets held at fair value on a recurring basis
Total gains (losses) included in: net income	15	74	36
Effect to net income reported in the Condensed Consolidated Statements of Operations and Comprehensive Income	15	74	36
Loss on disposition of operations
Rollforward of Level 3 assets held at fair value on a recurring basis
Total gains (losses) included in: net income	(4)	(6)
Effect to net income reported in the Condensed Consolidated Statements of Operations and Comprehensive Income	(4)	(6)
Fixed income securities
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation
Fair Value Measurement with Unobservable Inputs Reconciliation Recurring Basis Sale of Assets of Disposal Group Including Discontinued Operations	(4)
Gains (losses) for Level 3 assets still held at the balance sheet date, included in earnings	11	5	12
Rollforward of Level 3 assets held at fair value on a recurring basis
Balance at beginning of period	1,241	2,060	2,038
Total gains (losses) included in: net income	20	17	35
Total gains (losses) included in: OCI	7	20	154
Transfers into Level 3	101	101	476
Transfers out of Level 3	(147)	(188)	(128)
Transfer to held for sale		385
Purchases/Issues	41	145	137
Sales	(121)	(371)	(496)
Issues			0
Settlements	(118)	(158)	(156)
Balance at end of period	1,028	1,241	2,060
Effect to net income reported in the Condensed Consolidated Statements of Operations and Comprehensive Income	20	17	35
Municipal
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation
Fair Value Measurement with Unobservable Inputs Reconciliation Recurring Basis Sale of Assets of Disposal Group Including Discontinued Operations	0
Gains (losses) for Level 3 assets still held at the balance sheet date, included in earnings	(1)	(4)	0
Rollforward of Level 3 assets held at fair value on a recurring basis
Balance at beginning of period	119	338	387
Total gains (losses) included in: net income	0	(12)	(5)
Total gains (losses) included in: OCI	18	19	22
Transfers into Level 3	0	0	53
Transfers out of Level 3	(17)	0	(10)
Transfer to held for sale		51
Purchases/Issues	0	0	0
Sales	(11)	(173)	(107)
Issues			0
Settlements	(3)	(2)	(2)
Balance at end of period	106	119	338
Effect to net income reported in the Condensed Consolidated Statements of Operations and Comprehensive Income	0	(12)	(5)
Corporate
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation
Fair Value Measurement with Unobservable Inputs Reconciliation Recurring Basis Sale of Assets of Disposal Group Including Discontinued Operations	0
Gains (losses) for Level 3 assets still held at the balance sheet date, included in earnings	11	13	15
Rollforward of Level 3 assets held at fair value on a recurring basis
Balance at beginning of period	1,008	1,501	1,319
Total gains (losses) included in: net income	20	32	20
Total gains (losses) included in: OCI	(14)	(32)	63
Transfers into Level 3	85	84	381
Transfers out of Level 3	(114)	(172)	(64)
Transfer to held for sale		244
Purchases/Issues	20	145	125
Sales	(109)	(173)	(223)
Issues			0
Settlements	(104)	(133)	(120)
Balance at end of period	792	1,008	1,501
Effect to net income reported in the Condensed Consolidated Statements of Operations and Comprehensive Income	20	32	20
ABS
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation
Fair Value Measurement with Unobservable Inputs Reconciliation Recurring Basis Sale of Assets of Disposal Group Including Discontinued Operations	0
Gains (losses) for Level 3 assets still held at the balance sheet date, included in earnings	0	(2)	0
Rollforward of Level 3 assets held at fair value on a recurring basis
Balance at beginning of period	112	199	254
Total gains (losses) included in: net income	0	(2)	24
Total gains (losses) included in: OCI	3	30	59
Transfers into Level 3	16	17	42
Transfers out of Level 3	(12)	(16)	(7)
Transfer to held for sale		85
Purchases/Issues	21	0	11
Sales	0	(8)	(165)
Issues			0
Settlements	(11)	(23)	(19)
Balance at end of period	129	112	199
Effect to net income reported in the Condensed Consolidated Statements of Operations and Comprehensive Income	0	(2)	24
RMBS
Rollforward of Level 3 assets held at fair value on a recurring basis
Balance at beginning of period		0	47
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	(47)
Transfer to held for sale		0
Purchases/Issues		0	0
Sales		0	0
Issues			0
Settlements		0	0
Balance at end of period		0	0
Effect to net income reported in the Condensed Consolidated Statements of Operations and Comprehensive Income		0	0
CMBS
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation
Fair Value Measurement with Unobservable Inputs Reconciliation Recurring Basis Sale of Assets of Disposal Group Including Discontinued Operations	(4)
Gains (losses) for Level 3 assets still held at the balance sheet date, included in earnings	1	(2)	(3)
Rollforward of Level 3 assets held at fair value on a recurring basis
Balance at beginning of period	1	21	30
Total gains (losses) included in: net income	0	(1)	(4)
Total gains (losses) included in: OCI	0	3	10
Transfers into Level 3	0	0	0
Transfers out of Level 3	(4)	0	0
Transfer to held for sale		5
Purchases/Issues	0	0	0
Sales	0	(17)	0
Issues			0
Settlements	0	0	(15)
Balance at end of period	1	1	21
Effect to net income reported in the Condensed Consolidated Statements of Operations and Comprehensive Income	0	(1)	(4)
Redeemable preferred stock
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation
Fair Value Measurement with Unobservable Inputs Reconciliation Recurring Basis Sale of Assets of Disposal Group Including Discontinued Operations	0
Rollforward of Level 3 assets held at fair value on a recurring basis
Balance at beginning of period	1	1	1
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
Transfer to held for sale		0
Purchases/Issues	0	0	1
Sales	(1)	0	(1)
Issues			0
Settlements	0	0	0
Balance at end of period	0	1	1
Effect to net income reported in the Condensed Consolidated Statements of Operations and Comprehensive Income	0	0	0
Equity securities
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation
Fair Value Measurement with Unobservable Inputs Reconciliation Recurring Basis Sale of Assets of Disposal Group Including Discontinued Operations	0
Gains (losses) for Level 3 assets still held at the balance sheet date, included in earnings	0	0	0
Rollforward of Level 3 assets held at fair value on a recurring basis
Balance at beginning of period	6	7	14
Total gains (losses) included in: net income	0	0	0
Total gains (losses) included in: OCI	(1)	0	0
Transfers into Level 3	0	0	0
Transfers out of Level 3	(1)	0	0
Transfer to held for sale		0
Purchases/Issues	39	0	5
Sales	(6)	(1)	(12)
Issues			0
Settlements	0	0	0
Balance at end of period	37	6	7
Effect to net income reported in the Condensed Consolidated Statements of Operations and Comprehensive Income	0	0	0
Free-standing derivatives, net
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation
Fair Value Measurement with Unobservable Inputs Reconciliation Recurring Basis Sale of Assets of Disposal Group Including Discontinued Operations	0
Gains (losses) for Level 3 assets still held at the balance sheet date, included in earnings	5	10	6
Rollforward of Level 3 assets held at fair value on a recurring basis
Balance at beginning of period	(5)	(27)	(88)
Total gains (losses) included in: net income	0	19	25
Total gains (losses) included in: OCI	0	0	0
Transfers into Level 3	0	0	0
Transfers out of Level 3	0	0	0
Transfer to held for sale		0
Purchases/Issues	2	9	27
Sales	0	0	0
Issues			0
Settlements	(4)	(6)	9
Balance at end of period	(7)	(5)	(27)
Effect to net income reported in the Condensed Consolidated Statements of Operations and Comprehensive Income	0	19	25
Other assets
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation
Fair Value Measurement with Unobservable Inputs Reconciliation Recurring Basis Sale of Assets of Disposal Group Including Discontinued Operations	0
Gains (losses) for Level 3 assets still held at the balance sheet date, included in earnings	1	(1)	0
Rollforward of Level 3 assets held at fair value on a recurring basis
Balance at beginning of period	0	1	1
Total gains (losses) included in: net income	1	(1)	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
Transfer to held for sale		0
Purchases/Issues	0	0	0
Sales	0	0	0
Issues			0
Settlements	0	0	0
Balance at end of period	1	0	1
Effect to net income reported in the Condensed Consolidated Statements of Operations and Comprehensive Income	1	(1)	0
Assets held for sale
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation
Fair Value Measurement with Unobservable Inputs Reconciliation Recurring Basis Sale of Assets of Disposal Group Including Discontinued Operations	351
Gains (losses) for Level 3 assets still held at the balance sheet date, included in earnings	0	(2)	0
Rollforward of Level 3 assets held at fair value on a recurring basis
Balance at beginning of period	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)
Transfer to held for sale		(385)
Purchases/Issues	0	0
Sales	(8)	(10)
Settlements	(6)	(5)
Balance at end of period	0	362	0
Effect to net income reported in the Condensed Consolidated Statements of Operations and Comprehensive Income	(1)	(2)
Contractholder funds: Derivatives embedded in life and annuity contracts
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation
Fair Value Measurement With Unobservable Inputs Reconciliation Liability Transfers To Held For Sale		265
Liabilities held for sale
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation
Fair Value Measurement With Unobservable Inputs Reconciliation Liability Transfers To Held For Sale		$ (265)