Investments (Details 9) (USD $) In Millions, unless otherwise specified	Jun. 30, 2011	Dec. 31, 2010
CMBS by rating agency designations and by vintage year
Amortized Cost	$ 330,903	$ 317,617
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	341,744	324,797
Fixed maturity securities [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	330,903	317,617
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	341,744	324,797
% of Total	100.00%	100.00%
Ratings Distribution [Member] | Aaa [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
% of Total	82.80%	81.70%
Ratings Distribution [Member] | Aa [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
% of Total	8.00%	6.40%
Ratings Distribution [Member] | Baa [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
% of Total	2.80%	4.90%
Ratings Distribution [Member] | Below Investment Grade [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
% of Total	2.10%	2.20%
Ratings Distribution [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
% of Total	100.00%	100.00%
Vintage Year, 2003 & Prior [Member] | Aaa [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	6,311	7,411
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	6,481	7,640
Vintage Year, 2003 & Prior [Member] | Aa [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	184	282
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	186	282
Vintage Year, 2003 & Prior [Member] | A [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	105	228
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	103	227
Vintage Year, 2003 & Prior [Member] | Baa [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	63	74
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	61	71
Vintage Year, 2003 & Prior [Member] | Below Investment Grade [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	21	28
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	20	24
Vintage Year, 2003 & Prior [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	6,684	8,023
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	6,851	8,244
Vintage Year, 2005 [Member] | Aaa [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	2,905	3,113
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	3,141	3,292
Vintage Year, 2005 [Member] | Aa [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	363	322
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	389	324
Vintage Year, 2005 [Member] | A [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	307	286
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	325	280
Vintage Year, 2005 [Member] | Baa [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	169	263
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	175	255
Vintage Year, 2005 [Member] | Below Investment Grade [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	37	73
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	29	66
Vintage Year, 2005 [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	3,781	4,057
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	4,059	4,217
Vintage Year, 2004 [Member] | Aaa [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	3,693	3,489
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	3,858	3,620
Vintage Year, 2004 [Member] | Aa [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	462	277
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	483	273
Vintage Year, 2004 [Member] | A [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	117	216
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	115	209
Vintage Year, 2004 [Member] | Baa [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	91	181
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	92	175
Vintage Year, 2004 [Member] | Below Investment Grade [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	76	91
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	66	68
Vintage Year, 2004 [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	4,439	4,254
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	4,614	4,345
Vintage Year, 2006 [Member] | Aaa [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	1,480	1,463
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	1,584	1,545
Vintage Year, 2006 [Member] | Aa [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	155	159
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	157	160
Vintage Year, 2006 [Member] | A [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	86	168
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	94	168
Vintage Year, 2006 [Member] | Baa [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	153	385
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	165	398
Vintage Year, 2006 [Member] | Below Investment Grade [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	157	166
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	155	156
Vintage Year, 2006 [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	2,031	2,341
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	2,155	2,427
Vintage Year, 2007 [Member] | Aaa [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	674	840
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	687	791
Vintage Year, 2007 [Member] | Aa [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	369	344
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	342	298
Vintage Year, 2007 [Member] | A [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	155	96
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	151	95
Vintage Year, 2007 [Member] | Baa [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	43	119
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	44	108
Vintage Year, 2007 [Member] | Below Investment Grade [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	117	122
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	115	133
Vintage Year, 2007 [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	1,358	1,521
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	1,339	1,425
Vintage Year, 2008 [Member] | Aaa [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	0	2
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	0	2
Vintage Year, 2008 [Member] | Aa [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	0	0
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	0	0
Vintage Year, 2008 [Member] | A [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	0	0
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	0	0
Vintage Year, 2008 [Member] | Baa [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	0	0
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	0	0
Vintage Year, 2008 [Member] | Below Investment Grade [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	26	0
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	30	0
Vintage Year, 2008 [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	26	2
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	30	2
Vintage Year, 2009 [Member] | Aaa [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	2	3
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	2	3
Vintage Year, 2009 [Member] | Aa [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	0	0
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	0	0
Vintage Year, 2009 [Member] | A [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	0	0
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	0	0
Vintage Year, 2009 [Member] | Baa [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	0	0
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	0	0
Vintage Year, 2009 [Member] | Below Investment Grade [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	0	0
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	0	0
Vintage Year, 2009 [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	2	3
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	2	3
Vintage Year, 2010 [Member] | Aaa [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	3	8
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	3	8
Vintage Year, 2010 [Member] | Aa [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	0	0
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	0	0
Vintage Year, 2010 [Member] | A [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	56	4
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	61	4
Vintage Year, 2010 [Member] | Baa [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	0	0
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	0	0
Vintage Year, 2010 [Member] | Below Investment Grade [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	0	0
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	0	0
Vintage Year, 2010 [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	59	12
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	64	12
Vintage Year, 2011 [Member] | Aaa [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	402
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	404
Vintage Year, 2011 [Member] | Aa [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	0
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	0
Vintage Year, 2011 [Member] | A [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	0
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	0
Vintage Year, 2011 [Member] | Baa [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	0
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	0
Vintage Year, 2011 [Member] | Below Investment Grade [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	0
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	0
Vintage Year, 2011 [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	402
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	404
Aaa [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	15,470	16,329
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	16,160	16,901
Aa [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	1,533	1,384
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	1,557	1,337
A [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	826	998
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	849	983
% of Total	4.30%	4.80%
Baa [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	519	1,022
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	537	1,007
Below Investment Grade [Member] | CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	434	480
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	415	447
CMBS [Member]
CMBS by rating agency designations and by vintage year
Amortized Cost	18,782	20,213
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $330,903 and $317,617, respectively; includes $3,357 and $3,330, respectively, relating to variable interest entities)	$ 19,518	$ 20,675
% of Total	5.70%	6.40%