Insurance (Guarantees Related to Universal and Variable Life Contracts) (Details) - Universal and Variable Life Contracts - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Secondary Guarantees
Net Amount at Risk by Product and Guarantee [Line Items]
Total account value (3)	$ 17,273	$ 17,211
Net amount at risk (7)	$ 175,990	$ 175,958
Average attained age of policyholders	57 years	57 years
Paid-Up Guarantees
Net Amount at Risk by Product and Guarantee [Line Items]
Total account value (3)	$ 3,408	$ 3,461
Net amount at risk (7)	$ 18,514	$ 19,047
Average attained age of policyholders	62 years	62 years