Reinsurance (Effect of Reinsurance on Life Insurance In Force) (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Reinsurance Disclosures [Abstract]
Reinsurance Premiums for Insurance Companies, by Product Segment, Gross Amount	$ 1,686	$ 78	$ 77
Reinsurance Premiums for Insurance Companies, by Product Segment, Amount Assumed from Other Companies	2,995,079	2,943,517	2,889,804
Reinsurance Premiums for Insurance Companies, by Product Segment, Amount Ceded to Other Companies	222,388	230,544	36,830
Reinsurance Premiums for Insurance Companies, by Product Segment, Net Amount	$ 2,774,377	$ 2,713,051	$ 2,853,051
Reinsurance Premiums for Insurance Companies, by Product Segment, Percentage of Amount Assumed to Net	108.00%	108.50%	101.30%