Insurance (Guarantees Related to Annuity Contracts) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Variable Annuity Guarantees | Guaranteed Death Benefits [Member]
Net Amount at Risk by Product and Guarantee [Line Items]
Account value	$ 62,810	$ 62,763
Separate account value in event of death	51,077	50,700
Net amount at risk in event of death	702	641
Average attained age of contractholders	65 years	64 years
Variable Annuity Guarantees | Guaranteed Annuitization Benefits [Member]
Net Amount at Risk by Product and Guarantee [Line Items]
Account value	29,474	28,934
Separate account value at annuitization	28,347	27,738
Net amount at risk at annuitization	244	123
Average attained age of contractholders	63 years	62 years
Two Tier and Other Annuities | Guaranteed Annuitization Benefits [Member]
Net Amount at Risk by Product and Guarantee [Line Items]
Account value	456	397
Net amount at risk at annuitization	$ 153	$ 123
Average attained age of contractholders	55 years	54 years