Insurance (Details 2) (Universal and Variable Life Contracts [Member], USD $) In Millions, unless otherwise specified	9 Months Ended	12 Months Ended
	Sep. 30, 2012	Dec. 31, 2011
Secondary Guarantees [Member]
Net Amount at Risk by Product and Guarantee [Line Items]
Account value (general and separate account)	$ 14,007	$ 12,946
Net amount at risk	190,458	188,642
Average attained age of policyholders	54 years	53 years
Paid-Up Guarantees [Member]
Net Amount at Risk by Product and Guarantee [Line Items]
Account value (general and separate account)	3,861	3,963
Net amount at risk	$ 23,666	$ 24,991
Average attained age of policyholders	59 years	59 years