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, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Liability for future policy benefits and unpaid losses and loss adjustment expenses
Future policy benefits	$ 13,180	$ 12,988
Liability for Future Policy Benefits and Unpaid Claims and Claims Adjustment Expense	41,444	41,373
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	6,084	6,308
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	203	206
Individual Life [Member]
Liability for future policy benefits and unpaid losses and loss adjustment expenses
Group life other unpaid losses and loss adjustment expenses	171	167
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	$ 19,638	$ 19,669