Insurance (Guarantees Related to Annuity Contracts) (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Variable Annuities | Guaranteed Death Benefits
Net Amount at Risk by Product and Guarantee [Line Items]
Account value	$ 179,887	$ 196,595
Separate account value	149,829	163,566
Net amount at risk	$ 11,374	$ 4,230
Average attained age of contractholders	66 years	65 years
Variable Annuities | Guaranteed Annuitization Benefits
Net Amount at Risk by Product and Guarantee [Line Items]
Account value	$ 90,852	$ 99,000
Separate account value	87,417	95,963
Net amount at risk	$ 2,909	$ 1,770
Average attained age of contractholders	66 years	65 years
Two Tier and Other Annuities | Guaranteed Annuitization Benefits
Net Amount at Risk by Product and Guarantee [Line Items]
Account value	$ 1,621	$ 1,040
Net amount at risk	$ 444	$ 340
Average attained age of contractholders	53 years	50 years