Investments and Derivative Instruments (Details 4) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Security Unrealized Loss Aging
Less Than 12 Months, Amortized Cost	$ 2,363		$ 18,031
Less Than 12 Months, Fair Value	2,340		17,468
Less Than 12 Months, Unrealized Losses	(23)	(563)
12 Months or More, Amortized Cost	6,725		5,625
12 Months or More, Fair Value	6,400		5,109
12 Months or More, Unrealized Losses	(328)	(514)
Amortized Cost	9,088		23,656
Fair Value	8,740		22,577
Unrealized Losses	(351)	(1,077)
ABS [Member]
Security Unrealized Loss Aging
Less Than 12 Months, Amortized Cost	470		893
Less Than 12 Months, Fair Value	469		888
Less Than 12 Months, Unrealized Losses	(1)	(5)
12 Months or More, Amortized Cost	559		477
12 Months or More, Fair Value	520		418
12 Months or More, Unrealized Losses	(39)	(59)
Amortized Cost	1,029		1,370
Fair Value	989		1,306
Unrealized Losses	(40)	(64)
Collateralized Debt Obligations [Member]
Security Unrealized Loss Aging
Less Than 12 Months, Amortized Cost	237		137
Less Than 12 Months, Fair Value	236		135
Less Than 12 Months, Unrealized Losses	(1)	(2)
12 Months or More, Amortized Cost	1,719		1,933
12 Months or More, Fair Value	1,676		1,874
12 Months or More, Unrealized Losses	(46)	(57)
Amortized Cost	1,956		2,070
Fair Value	1,912		2,009
Unrealized Losses	(47)	(59)
CMBS [Member]
Security Unrealized Loss Aging
Less Than 12 Months, Amortized Cost	100		812
Less Than 12 Months, Fair Value	98		788
Less Than 12 Months, Unrealized Losses	(2)	(24)
12 Months or More, Amortized Cost	587		610
12 Months or More, Fair Value	564		576
12 Months or More, Unrealized Losses	(23)	(34)
Amortized Cost	687		1,422
Fair Value	662		1,364
Unrealized Losses	(25)	(58)
Corporate [Member]
Security Unrealized Loss Aging
Less Than 12 Months, Amortized Cost	682		4,922
Less Than 12 Months, Fair Value	673		4,737
Less Than 12 Months, Unrealized Losses	(9)	(185)
12 Months or More, Amortized Cost	1,683		1,225
12 Months or More, Fair Value	1,567		1,064
12 Months or More, Unrealized Losses	(116)	(161)
Amortized Cost	2,365		6,147
Fair Value	2,240		5,801
Unrealized Losses	(125)	(346)
Foreign Government Debt Securities [Member]
Security Unrealized Loss Aging
Less Than 12 Months, Amortized Cost	129		2,961
Less Than 12 Months, Fair Value	128		2,868
Less Than 12 Months, Unrealized Losses	(1)	(93)
12 Months or More, Amortized Cost	322		343
12 Months or More, Fair Value	301		260
12 Months or More, Unrealized Losses	(21)	(83)
Amortized Cost	451		3,304
Fair Value	429		3,128
Unrealized Losses	(22)	(176)
Municipal [Member]
Security Unrealized Loss Aging
Less Than 12 Months, Amortized Cost	119		3,150
Less Than 12 Months, Fair Value	118		2,994
Less Than 12 Months, Unrealized Losses	(1)	(156)
12 Months or More, Amortized Cost	490		190
12 Months or More, Fair Value	475		162
12 Months or More, Unrealized Losses	(15)	(28)
Amortized Cost	609		3,340
Fair Value	593		3,156
Unrealized Losses	(16)	(184)
RMBS [Member]
Security Unrealized Loss Aging
Less Than 12 Months, Amortized Cost	285		2,046
Less Than 12 Months, Fair Value	283		2,008
Less Than 12 Months, Unrealized Losses	(2)	(38)
12 Months or More, Amortized Cost	645		591
12 Months or More, Fair Value	614		547
12 Months or More, Unrealized Losses	(31)	(44)
Amortized Cost	930		2,637
Fair Value	897		2,555
Unrealized Losses	(33)	(82)
U.S. Treasuries [Member]
Security Unrealized Loss Aging
Less Than 12 Months, Amortized Cost	289		2,914
Less Than 12 Months, Fair Value	288		2,862
Less Than 12 Months, Unrealized Losses	(1)	(52)
12 Months or More, Amortized Cost	492		33
12 Months or More, Fair Value	483		26
12 Months or More, Unrealized Losses	(9)	(7)
Amortized Cost	781		2,947
Fair Value	771		2,888
Unrealized Losses	(10)	(59)
Fixed maturities [Member]
Security Unrealized Loss Aging
Less Than 12 Months, Amortized Cost	2,311		17,835
Less Than 12 Months, Fair Value	2,293		17,280
Less Than 12 Months, Unrealized Losses	(18)	(555)
12 Months or More, Amortized Cost	6,497		5,402
12 Months or More, Fair Value	6,200		4,927
12 Months or More, Unrealized Losses	(300)	(473)
Amortized Cost	8,808		23,237
Fair Value	8,493		22,207
Unrealized Losses	(318)	(1,028)
Equity Securities [Member]
Security Unrealized Loss Aging
Less Than 12 Months, Amortized Cost	52		196
Less Than 12 Months, Fair Value	47		188
Less Than 12 Months, Unrealized Losses	(5)	(8)
12 Months or More, Amortized Cost	228		223
12 Months or More, Fair Value	200		182
12 Months or More, Unrealized Losses	(28)	(41)
Amortized Cost	280		419
Fair Value	247		370
Unrealized Losses	$ (33)	$ (49)