Variable Annuity and Insurance Guarantees (Details 3) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Mutual funds
Distribution of separate account balances by asset type for variable annuity contracts providing guaranteed benefits:
Total mutual funds	$ 64,061	$ 62,210
Equity
Distribution of separate account balances by asset type for variable annuity contracts providing guaranteed benefits:
Total mutual funds	33,375	32,054
Bond
Distribution of separate account balances by asset type for variable annuity contracts providing guaranteed benefits:
Total mutual funds	26,477	26,165
Other
Distribution of separate account balances by asset type for variable annuity contracts providing guaranteed benefits:
Total mutual funds	$ 4,209	$ 3,991