Shareholders' Equity And Dividend Restrictions (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Shareholders Equity And Dividend Restrictions [Abstract]
Declared cash dividends, per share	$ 1.92	$ 2.3	$ 1.76
Dividends declared by insurance subsidiary to parent	$ 475	$ 447	$ 400
Dividend payment without prior regulatory approval, Minimum percent of policyholder surplus	10.00%
Dividend payment without prior regulatory approval, percent of statutory net income for the prior calendar year	100.00%
Dividends might be paid during next year	$ 469