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	Dec. 31, 2014	Dec. 31, 2013
Account Balances Of Variable Annuity Contracts With Guarantees Invested In Separate Accounts [Line Items]
Total	$ 107,866	$ 100,856
Percent of total variable annuity separate account values	99.00%	98.00%
Domestic equity
Account Balances Of Variable Annuity Contracts With Guarantees Invested In Separate Accounts [Line Items]
Total	49,569	47,042
International equity
Account Balances Of Variable Annuity Contracts With Guarantees Invested In Separate Accounts [Line Items]
Total	18,791	18,341
Bonds
Account Balances Of Variable Annuity Contracts With Guarantees Invested In Separate Accounts [Line Items]
Total	26,808	24,547
Money Market
Account Balances Of Variable Annuity Contracts With Guarantees Invested In Separate Accounts [Line Items]
Total	$ 12,698	$ 10,926