Federal Income Taxes (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Effective tax rate	19.00%	24.00%	24.00%
Federal rate	35.00%
Dividends-received deduction	$ 192	$ 163	$ 145
Net operating loss carryforwards	$ 34
Net Operating Loss Carryforward Beginning Expiration Date	2031
Unrecognized tax benefits, that, if recognized, would impact income tax expense and effective tax rate	$ 13	15
Recognized interest and penalty expense related to uncertain tax positions	0	(10)	$ 2
Accrued interest and penalty expense related to unrecognized tax benefits	3	$ 3
Alternative Minimum [Member]
Tax Credit Carryforward, Amount	$ 33