Shareholders' Equity And Dividend Restrictions (Narrative) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Shareholder's Equity And Dividend Restrictions [Abstract]
Dividends declared by insurance subsidiary to parent	$ 300	$ 180	$ 220
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 2013	$ 391
Declared cash dividends, per share	$ 1.62	$ 1.605	$ 1.59
Shares of common stock, available for future equity award grants	9.3