Fair Value Measurements (Details) - USD ($) $ in Millions		Jun. 30, 2016	Dec. 31, 2015
Assets:
Available for sale (AFS) fixed maturities		$ 34,638	$ 32,284
Trading fixed maturities		271	254
Assets of managed investment entities (“MIE”)		4,410	4,047
Variable annuity assets (separate accounts)	[1]	595	608
Total assets accounted for at fair value		41,858	39,155
Liabilities:
Liabilities of managed investment entities		4,192	3,781
Total liabilities accounted for at fair value		5,753	5,156
Annuity benefits accumulated [Member]
Liabilities:
Derivatives included in annuity benefits accumulated, long-term debt, and other liabilities		1,557	1,369
Derivatives in long-term debt [Member]
Liabilities:
Derivatives included in annuity benefits accumulated, long-term debt, and other liabilities		(9)	(2)
Other liabilities — derivatives [Member]
Liabilities:
Derivatives included in annuity benefits accumulated, long-term debt, and other liabilities		13	8
U.S. Government and government agencies [Member]
Assets:
Available for sale (AFS) fixed maturities		338	307
States, municipalities and political subdivisions [Member]
Assets:
Available for sale (AFS) fixed maturities		7,139	6,856
Foreign government [Member]
Assets:
Available for sale (AFS) fixed maturities		143	154
Residential Mortgage Backed Securities [Member]
Assets:
Available for sale (AFS) fixed maturities		3,747	3,529
Commercial Mortgage Backed Securities [Member]
Assets:
Available for sale (AFS) fixed maturities		2,042	2,187
Asset-backed Securities [Member]
Assets:
Available for sale (AFS) fixed maturities		5,500	4,934
All other corporate [Member]
Assets:
Available for sale (AFS) fixed maturities		15,729	14,317
Fixed maturities [Member]
Assets:
Available for sale (AFS) fixed maturities		34,638	32,284
Trading fixed maturities		271	254
Equity securities [Member]
Assets:
Equity securities — AFS and trading		1,558	1,719
Other assets — derivatives [Member]
Assets:
Derivatives included in other investments and other assets		18	2
Level 1 [Member]
Assets:
Assets of managed investment entities (“MIE”)		338	309
Variable annuity assets (separate accounts)	[1]	0	0
Total assets accounted for at fair value		1,796	1,834
Liabilities:
Liabilities of managed investment entities		322	289
Total liabilities accounted for at fair value		322	289
Level 1 [Member] | Annuity benefits accumulated [Member]
Liabilities:
Derivatives included in annuity benefits accumulated, long-term debt, and other liabilities		0	0
Level 1 [Member] | Derivatives in long-term debt [Member]
Liabilities:
Derivatives included in annuity benefits accumulated, long-term debt, and other liabilities		0	0
Level 1 [Member] | Other liabilities — derivatives [Member]
Liabilities:
Derivatives included in annuity benefits accumulated, long-term debt, and other liabilities		0	0
Level 1 [Member] | U.S. Government and government agencies [Member]
Assets:
Available for sale (AFS) fixed maturities		103	100
Level 1 [Member] | States, municipalities and political subdivisions [Member]
Assets:
Available for sale (AFS) fixed maturities		0	0
Level 1 [Member] | Foreign government [Member]
Assets:
Available for sale (AFS) fixed maturities		0	0
Level 1 [Member] | Residential Mortgage Backed Securities [Member]
Assets:
Available for sale (AFS) fixed maturities		0	0
Level 1 [Member] | Commercial Mortgage Backed Securities [Member]
Assets:
Available for sale (AFS) fixed maturities		0	0
Level 1 [Member] | Asset-backed Securities [Member]
Assets:
Available for sale (AFS) fixed maturities		0	0
Level 1 [Member] | All other corporate [Member]
Assets:
Available for sale (AFS) fixed maturities		38	50
Level 1 [Member] | Fixed maturities [Member]
Assets:
Available for sale (AFS) fixed maturities		141	150
Trading fixed maturities		12	13
Level 1 [Member] | Equity securities [Member]
Assets:
Equity securities — AFS and trading		1,305	1,362
Level 1 [Member] | Other assets — derivatives [Member]
Assets:
Derivatives included in other investments and other assets		0	0
Level 2 [Member]
Assets:
Assets of managed investment entities (“MIE”)		4,046	3,712
Variable annuity assets (separate accounts)	[1]	595	608
Total assets accounted for at fair value		38,337	35,685
Liabilities:
Liabilities of managed investment entities		3,846	3,468
Total liabilities accounted for at fair value		3,850	3,474
Level 2 [Member] | Annuity benefits accumulated [Member]
Liabilities:
Derivatives included in annuity benefits accumulated, long-term debt, and other liabilities		0	0
Level 2 [Member] | Derivatives in long-term debt [Member]
Liabilities:
Derivatives included in annuity benefits accumulated, long-term debt, and other liabilities		(9)	(2)
Level 2 [Member] | Other liabilities — derivatives [Member]
Liabilities:
Derivatives included in annuity benefits accumulated, long-term debt, and other liabilities		13	8
Level 2 [Member] | U.S. Government and government agencies [Member]
Assets:
Available for sale (AFS) fixed maturities		227	192
Level 2 [Member] | States, municipalities and political subdivisions [Member]
Assets:
Available for sale (AFS) fixed maturities		7,048	6,767
Level 2 [Member] | Foreign government [Member]
Assets:
Available for sale (AFS) fixed maturities		143	154
Level 2 [Member] | Residential Mortgage Backed Securities [Member]
Assets:
Available for sale (AFS) fixed maturities		3,516	3,305
Level 2 [Member] | Commercial Mortgage Backed Securities [Member]
Assets:
Available for sale (AFS) fixed maturities		2,006	2,148
Level 2 [Member] | Asset-backed Securities [Member]
Assets:
Available for sale (AFS) fixed maturities		5,022	4,464
Level 2 [Member] | All other corporate [Member]
Assets:
Available for sale (AFS) fixed maturities		15,002	13,634
Level 2 [Member] | Fixed maturities [Member]
Assets:
Available for sale (AFS) fixed maturities		32,964	30,664
Trading fixed maturities		259	241
Level 2 [Member] | Equity securities [Member]
Assets:
Equity securities — AFS and trading		87	217
Level 2 [Member] | Other assets — derivatives [Member]
Assets:
Derivatives included in other investments and other assets		18	2
Level 3 [Member]
Assets:
Assets of managed investment entities (“MIE”)		26	26
Variable annuity assets (separate accounts)	[1]	0	0
Total assets accounted for at fair value		1,725	1,636
Liabilities:
Liabilities of managed investment entities		24	24
Total liabilities accounted for at fair value		1,581	1,393
Level 3 [Member] | Annuity benefits accumulated [Member]
Liabilities:
Derivatives included in annuity benefits accumulated, long-term debt, and other liabilities		1,557	1,369
Level 3 [Member] | Derivatives in long-term debt [Member]
Liabilities:
Derivatives included in annuity benefits accumulated, long-term debt, and other liabilities		0	0
Level 3 [Member] | Other liabilities — derivatives [Member]
Liabilities:
Derivatives included in annuity benefits accumulated, long-term debt, and other liabilities		0	0
Level 3 [Member] | U.S. Government and government agencies [Member]
Assets:
Available for sale (AFS) fixed maturities		8	15
Level 3 [Member] | States, municipalities and political subdivisions [Member]
Assets:
Available for sale (AFS) fixed maturities		91	89
Level 3 [Member] | Foreign government [Member]
Assets:
Available for sale (AFS) fixed maturities		0	0
Level 3 [Member] | Residential Mortgage Backed Securities [Member]
Assets:
Available for sale (AFS) fixed maturities		231	224
Level 3 [Member] | Commercial Mortgage Backed Securities [Member]
Assets:
Available for sale (AFS) fixed maturities		36	39
Level 3 [Member] | Asset-backed Securities [Member]
Assets:
Available for sale (AFS) fixed maturities		478	470
Level 3 [Member] | All other corporate [Member]
Assets:
Available for sale (AFS) fixed maturities		689	633
Level 3 [Member] | Fixed maturities [Member]
Assets:
Available for sale (AFS) fixed maturities		1,533	1,470
Trading fixed maturities		0	0
Level 3 [Member] | Equity securities [Member]
Assets:
Equity securities — AFS and trading		166	140
Level 3 [Member] | Other assets — derivatives [Member]
Assets:
Derivatives included in other investments and other assets		0	0
Equity index call options [Member] | Other investments — derivatives [Member]
Assets:
Derivatives included in other investments and other assets		368	241
Equity index call options [Member] | Level 1 [Member] | Other investments — derivatives [Member]
Assets:
Derivatives included in other investments and other assets		0	0
Equity index call options [Member] | Level 2 [Member] | Other investments — derivatives [Member]
Assets:
Derivatives included in other investments and other assets		368	241
Equity index call options [Member] | Level 3 [Member] | Other investments — derivatives [Member]
Assets:
Derivatives included in other investments and other assets		$ 0	$ 0

[1] Variable annuity liabilities equal the fair value of variable annuity assets.