Shareholders' Equity (Schedule Of Common Stock Outstanding Roll Forward) (Details)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Shares issued:
Shares issued at beginning of year	40,003,642
Shares cancelled, shares	(3,633,774)
Shares issued at end of year	36,369,868	40,003,642
Treasury shares:
Treasury shares issued at beginning of year	2,261,511
Shares repurchased, shares	3,655,959	1,419,163
Shares issued out of treasury	(711,609)
Shares cancelled, shares	(3,633,774)
Total treasury shares at end of year	1,572,087	2,261,511
Total shares outstanding at end of year	34,797,781	37,742,131