Investments and Derivative Instruments (Details 4) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Security Unrealized Loss Aging
Less Than 12 Months, Amortized Cost	$ 9,249		$ 18,031
Less Than 12 Months, Fair Value	9,048		17,468
Less Than 12 Months, Unrealized Losses	(201)	(563)
12 Months or More, Amortized Cost	5,529		5,625
12 Months or More, Fair Value	5,089		5,109
12 Months or More, Unrealized Losses	(437)	(514)
Amortized Cost	14,778		23,656
Fair Value	14,137		22,577
Unrealized Losses	(638)	(1,077)
ABS [Member]
Security Unrealized Loss Aging
Less Than 12 Months, Amortized Cost	595		893
Less Than 12 Months, Fair Value	592		888
Less Than 12 Months, Unrealized Losses	(3)	(5)
12 Months or More, Amortized Cost	454		477
12 Months or More, Fair Value	406		418
12 Months or More, Unrealized Losses	(48)	(59)
Amortized Cost	1,049		1,370
Fair Value	998		1,306
Unrealized Losses	(51)	(64)
Collateralized Debt Obligations [Member]
Security Unrealized Loss Aging
Less Than 12 Months, Amortized Cost	222		137
Less Than 12 Months, Fair Value	219		135
Less Than 12 Months, Unrealized Losses	(3)	(2)
12 Months or More, Amortized Cost	1,842		1,933
12 Months or More, Fair Value	1,789		1,874
12 Months or More, Unrealized Losses	(50)	(57)
Amortized Cost	2,064		2,070
Fair Value	2,008		2,009
Unrealized Losses	(53)	(59)
CMBS [Member]
Security Unrealized Loss Aging
Less Than 12 Months, Amortized Cost	619		812
Less Than 12 Months, Fair Value	605		788
Less Than 12 Months, Unrealized Losses	(14)	(24)
12 Months or More, Amortized Cost	567		610
12 Months or More, Fair Value	540		576
12 Months or More, Unrealized Losses	(27)	(34)
Amortized Cost	1,186		1,422
Fair Value	1,145		1,364
Unrealized Losses	(41)	(58)
Corporate [Member]
Security Unrealized Loss Aging
Less Than 12 Months, Amortized Cost	2,884		4,922
Less Than 12 Months, Fair Value	2,812		4,737
Less Than 12 Months, Unrealized Losses	(72)	(185)
12 Months or More, Amortized Cost	1,241		1,225
12 Months or More, Fair Value	1,105		1,064
12 Months or More, Unrealized Losses	(136)	(161)
Amortized Cost	4,125		6,147
Fair Value	3,917		5,801
Unrealized Losses	(208)	(346)
Foreign Government Debt Securities [Member]
Security Unrealized Loss Aging
Less Than 12 Months, Amortized Cost	1,173		2,961
Less Than 12 Months, Fair Value	1,139		2,868
Less Than 12 Months, Unrealized Losses	(34)	(93)
12 Months or More, Amortized Cost	390		343
12 Months or More, Fair Value	309		260
12 Months or More, Unrealized Losses	(81)	(83)
Amortized Cost	1,563		3,304
Fair Value	1,448		3,128
Unrealized Losses	(115)	(176)
Municipal [Member]
Security Unrealized Loss Aging
Less Than 12 Months, Amortized Cost	1,089		3,150
Less Than 12 Months, Fair Value	1,053		2,994
Less Than 12 Months, Unrealized Losses	(36)	(156)
12 Months or More, Amortized Cost	252		190
12 Months or More, Fair Value	230		162
12 Months or More, Unrealized Losses	(22)	(28)
Amortized Cost	1,341		3,340
Fair Value	1,283		3,156
Unrealized Losses	(58)	(184)
RMBS [Member]
Security Unrealized Loss Aging
Less Than 12 Months, Amortized Cost	1,292		2,046
Less Than 12 Months, Fair Value	1,274		2,008
Less Than 12 Months, Unrealized Losses	(18)	(38)
12 Months or More, Amortized Cost	533		591
12 Months or More, Fair Value	497		547
12 Months or More, Unrealized Losses	(36)	(44)
Amortized Cost	1,825		2,637
Fair Value	1,771		2,555
Unrealized Losses	(54)	(82)
U.S. Treasuries [Member]
Security Unrealized Loss Aging
Less Than 12 Months, Amortized Cost	1,275		2,914
Less Than 12 Months, Fair Value	1,260		2,862
Less Than 12 Months, Unrealized Losses	(15)	(52)
12 Months or More, Amortized Cost	33		33
12 Months or More, Fair Value	28		26
12 Months or More, Unrealized Losses	(5)	(7)
Amortized Cost	1,308		2,947
Fair Value	1,288		2,888
Unrealized Losses	(20)	(59)
Fixed maturities [Member]
Security Unrealized Loss Aging
Less Than 12 Months, Amortized Cost	9,149		17,835
Less Than 12 Months, Fair Value	8,954		17,280
Less Than 12 Months, Unrealized Losses	(195)	(555)
12 Months or More, Amortized Cost	5,312		5,402
12 Months or More, Fair Value	4,904		4,927
12 Months or More, Unrealized Losses	(405)	(473)
Amortized Cost	14,461		23,237
Fair Value	13,858		22,207
Unrealized Losses	(600)	(1,028)
Equity Securities [Member]
Security Unrealized Loss Aging
Less Than 12 Months, Amortized Cost	100		196
Less Than 12 Months, Fair Value	94		188
Less Than 12 Months, Unrealized Losses	(6)	(8)
12 Months or More, Amortized Cost	217		223
12 Months or More, Fair Value	185		182
12 Months or More, Unrealized Losses	(32)	(41)
Amortized Cost	317		419
Fair Value	279		370
Unrealized Losses	$ (38)	$ (49)