Reserves for Future Policy Benefits and Unpaid Losses and Loss Adjustment Expenses Level 4 Life Liabilities for Unpaid Losses and Loss Adjustment Expenses (Details) - Group Insurance Policies [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Liability for Claims and Claims Adjustment Expense	$ 5,965	$ 6,084	$ 6,308	$ 6,547
Reinsurance Recoverable for Unpaid Claims and Claims Adjustments	285	271	267	252
Beginning liabilities for unpaid losses and loss adjustment expenses, net	5,680	5,813	6,041	$ 6,295
Current Year Claims and Claims Adjustment Expense	2,371	2,370	2,534
Liability for Unpaid Claims and Claims Adjustment Expense, Period Increase (Decrease)	64	(11)	(17)
Liability for Unpaid Claims and Claims Adjustment Expense, Incurred Claims	2,435	2,359	2,517
Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid, Current Year	1,214	1,161	1,207
Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid, Prior Years	1,354	1,426	1,564
Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid	$ 2,568	$ 2,587	$ 2,771