Variable Annuity and Insurance Guarantees (Separate Account Balance by Type) (Details 5) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Mutual funds
Distribution of separate account balances by asset type for variable annuity contracts providing guaranteed benefits:
Total mutual funds	$ 74,584	$ 66,522
Equity
Distribution of separate account balances by asset type for variable annuity contracts providing guaranteed benefits:
Total mutual funds	44,739	39,764
Bond
Distribution of separate account balances by asset type for variable annuity contracts providing guaranteed benefits:
Total mutual funds	23,374	21,190
Other
Distribution of separate account balances by asset type for variable annuity contracts providing guaranteed benefits:
Total mutual funds	$ 6,471	$ 5,568