Investments (Details 7) (USD $) In Millions, unless otherwise specified	Jun. 30, 2011	Dec. 31, 2010
Alt-A RMBS by vintage year and certain other selected data
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]
Alt-A RMBS by vintage year and certain other selected data
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%
Alternative residential mortgage loans [Member] | RMBS [Member]
Alt-A RMBS by vintage year and certain other selected data
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)	4,760	4,221
% of Total	10.90%	9.40%
RMBS [Member]
Alt-A RMBS by vintage year and certain other selected data
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)	43,550	44,733
% of Total	12.80%	13.80%
Vintage Year, 2005 [Member] | Alternative residential mortgage loans [Member]
Alt-A RMBS by vintage year and certain other selected data
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)	1,704	1,576
% of Total	35.80%	37.30%
Vintage Year, 2006 [Member] | Alternative residential mortgage loans [Member]
Alt-A RMBS by vintage year and certain other selected data
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)	1,376	1,013
% of Total	28.90%	24.00%
Vintage Year, 2007 [Member] | Alternative residential mortgage loans [Member]
Alt-A RMBS by vintage year and certain other selected data
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)	1,016	922
% of Total	21.30%	21.80%
Vintage Year, 2008 [Member] | Alternative residential mortgage loans [Member]
Alt-A RMBS by vintage year and certain other selected data
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	7
% of Total	0.00%	0.20%
Vintage Year, 2009 [Member] | Alternative residential mortgage loans [Member]
Alt-A RMBS by vintage year and certain other selected data
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)	627	671
% of Total	13.20%	15.90%
Vintage Year, 2010 [Member] | Alternative residential mortgage loans [Member]
Alt-A RMBS by vintage year and certain other selected data
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)	37	32
% of Total	0.80%	0.80%
Vintage Year, 2011 [Member] | Alternative residential mortgage loans [Member]
Alt-A RMBS by vintage year and certain other selected data
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
% of Total	0.00%	0.00%
Alternative residential mortgage loans [Member]
Alt-A RMBS by vintage year and certain other selected data
% of Total	100.00%	100.00%