Insurance (Details 1) (Variable Annuity Guarantees [Member], USD $) In Millions, unless otherwise specified	6 Months Ended	12 Months Ended
	Jun. 30, 2012 Age	Dec. 31, 2011 Age
Guaranteed Death Benefits [Member]
Net Amount at Risk by Product and Guarantee [Line Items]
Account value	$ 173,414	$ 163,845
Separate account value in event of death	133,114	121,841
Net amount at risk in event of death	13,667	16,641
Average attained age of contract holders	62	62
Guaranteed Annuitization Benefits [Member]
Net Amount at Risk by Product and Guarantee [Line Items]
Account value	80,272	72,016
Average attained age of contract holders	62	61
Separate account value at annuitization	75,717	66,739
Net amount at risk at annuitization	3,310	2,686
Net amount at risk at annuitization for variable annuity guarantees based on the excess of the benefit base over the contractholder's total contract account value on the balance sheet date	11,100	12,100
Two Tier Annuities [Member] | Guaranteed Annuitization Benefits [Member]
Net Amount at Risk by Product and Guarantee [Line Items]
Account value	401	386
Average attained age of contract holders	61	60
Net amount at risk at annuitization	$ 59	$ 60