Separate Accounts, Death Benefits and Other Insurance Benefit Features (Details 2) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Variable separate accounts	$ 67,227	$ 68,988
Equity securities (including mutual funds) [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Variable separate accounts	60,631	61,472
Cash and cash equivalents [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Variable separate accounts	$ 6,596	$ 7,516