Guaranteed Benefit Features (Account Balances Of Variable Annuity Contracts With Guarantees Invested In Separate Accounts) (Details) (Variable Annuity [Member], USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Account Balances Of Variable Annuity Contracts With Guarantees Invested In Separate Accounts [Line Items]
Total	$ 94,079	$ 81,670
Percent of total variable annuity separate account values	98.00%	98.00%
Domestic equity [Member]
Account Balances Of Variable Annuity Contracts With Guarantees Invested In Separate Accounts [Line Items]
Total	43,552	37,899
International equity [Member]
Account Balances Of Variable Annuity Contracts With Guarantees Invested In Separate Accounts [Line Items]
Total	17,097	14,850
Bonds [Member]
Account Balances Of Variable Annuity Contracts With Guarantees Invested In Separate Accounts [Line Items]
Total	23,417	21,174
Money Market [Member]
Account Balances Of Variable Annuity Contracts With Guarantees Invested In Separate Accounts [Line Items]
Total	$ 10,013	$ 7,747