Investments and Derivative Instruments (Details 3) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Available-for-Sale Securities
Cost or Amortized Cost	$ 81,022	$ 80,034
Gross Unrealized Gains	5,334	5,442
Gross Unrealized Losses	(2,218)	(2,674)
Fair Value	84,095	82,730
Non-Credit OTTI	(184)	(187)
ABS [Member]
Available-for-Sale Securities
Cost or Amortized Cost	3,346	3,430
Gross Unrealized Gains	47	55
Gross Unrealized Losses	(306)	(332)
Fair Value	3,087	3,153
Non-Credit OTTI	(6)	(7)
CDOs [Member]
Available-for-Sale Securities
Cost or Amortized Cost	3,351	2,819
Gross Unrealized Gains	40	16
Gross Unrealized Losses	(305)	(348)
Fair Value	3,043	2,487
Non-Credit OTTI	(43)	(44)
CMBS [Member]
Available-for-Sale Securities
Cost or Amortized Cost	6,847	7,192
Gross Unrealized Gains	305	271
Gross Unrealized Losses	(378)	(512)
Fair Value	6,774	6,951
Non-Credit OTTI	(25)	(31)
Corporate [Member]
Available-for-Sale Securities
Cost or Amortized Cost	40,383	41,161
Gross Unrealized Gains	3,508	3,661
Gross Unrealized Losses	(562)	(739)
Fair Value	43,329	44,011
Non-Credit OTTI	(2)	0
Foreign govt./govt. agencies [Member]
Available-for-Sale Securities
Cost or Amortized Cost	3,248	2,030
Gross Unrealized Gains	128	141
Gross Unrealized Losses	(24)	(10)
Fair Value	3,352	2,161
Non-Credit OTTI	0	0
Municipal [Member]
Available-for-Sale Securities
Cost or Amortized Cost	12,991	12,557
Gross Unrealized Gains	914	775
Gross Unrealized Losses	(67)	(72)
Fair Value	13,838	13,260
Non-Credit OTTI	0	0
RMBS [Member]
Available-for-Sale Securities
Cost or Amortized Cost	6,778	5,961
Gross Unrealized Gains	240	252
Gross Unrealized Losses	(423)	(456)
Fair Value	6,595	5,757
Non-Credit OTTI	(108)	(105)
U.S. Treasuries [Member]
Available-for-Sale Securities
Cost or Amortized Cost	3,077	3,828
Gross Unrealized Gains	83	203
Gross Unrealized Losses	(21)	(2)
Fair Value	3,139	4,029
Non-Credit OTTI	0	0
Fixed maturities [Member]
Available-for-Sale Securities
Cost or Amortized Cost	80,021	78,978
Gross Unrealized Gains	5,265	5,374
Gross Unrealized Losses	(2,086)	(2,471)
Fair Value	83,157	81,809
Non-Credit OTTI	(184)	(187)
Equity Securities, AFS [Member]
Available-for-Sale Securities
Cost or Amortized Cost	1,001	1,056
Gross Unrealized Gains	69	68
Gross Unrealized Losses	(132)	(203)
Fair Value	938	921
Non-Credit OTTI	$ 0	$ 0