Reserves for Future Policy Benefits and Unpaid Losses and Loss Adjustment Expenses Level 4 Liability for Future Policy Benefits and Unpaid Losses and Loss Adjustment Expenses (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Liability for future policy benefits and unpaid losses and loss adjustment expenses
Future policy benefits	$ 13,351	$ 13,180
Liability for Future Policy Benefits and Unpaid Claims and Claims Adjustment Expense	41,572	41,444
group life term, disability and accident [Member]
Liability for future policy benefits and unpaid losses and loss adjustment expenses
Group life term, disability and accident unpaid losses and loss adjustment expenses	5,965	6,084
group life other [Member]
Liability for future policy benefits and unpaid losses and loss adjustment expenses
Group life other unpaid losses and loss adjustment expenses	174	203
Individual Life [Member]
Liability for future policy benefits and unpaid losses and loss adjustment expenses
Group life other unpaid losses and loss adjustment expenses	257	171
Group, life and future policy benefits [Member]
Liability for future policy benefits and unpaid losses and loss adjustment expenses
Liability for Future Policy Benefits and Unpaid Claims and Claims Adjustment Expense	$ 19,747	$ 19,638