Separate Accounts, Death Benefits and Other Insurance Benefit Features (Details 2) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Variable separate accounts	$ 63,369	$ 65,148
Equity securities (including mutual funds)
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Variable separate accounts	57,031	58,208
Cash and cash equivalents
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Variable separate accounts	$ 6,338	$ 6,940