Variable Annuity and Insurance Guarantees (Separate Account Balances by Type) (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Mutual funds
Variable Annuity and Insurance Guarantees
Total mutual funds	$ 68,968	$ 68,747
Equity [Member]
Variable Annuity and Insurance Guarantees
Total mutual funds	40,061	39,806
Bond [Member]
Variable Annuity and Insurance Guarantees
Total mutual funds	23,659	23,700
Other [Member]
Variable Annuity and Insurance Guarantees
Total mutual funds	$ 5,248	$ 5,241