Insurance (Guarantees Related to Annuity Contracts) (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
Variable Annuities | Guaranteed Death Benefits
Net Amount at Risk by Product and Guarantee [Line Items]
Account value	$ 193,102	$ 196,595
Separate account value	161,952	163,566
Net amount at risk	$ 5,107	$ 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	$ 97,772	$ 99,000
Separate account value	94,416	95,963
Net amount at risk	$ 1,821	$ 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	$ 958	$ 1,040
Net amount at risk	$ 281	$ 340
Average attained age of contractholders	51 years	50 years