Shareholders' Equity (Schedule Of Common Stock Outstanding Roll Forward) (Details) - shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Stockholders' Equity Note [Abstract]
Stock Repurchased and Retired During Period, Shares	(1,936,812)	(5,252,026)
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Shares issued at beginning of year	95,523,230	100,775,256
Shares cancelled, shares	(1,936,812)	(5,252,026)
Shares issued at end of year	93,586,418	95,523,230	100,775,256
Treasury Stock Transactions, Excluding Value of Shares Reissued [Abstract]
Treasury shares issued at beginning of year	4,563,595	4,579,774
Shares repurchased, shares	4,669,513	6,047,437	4,906,785
Shares issued out of treasury	(807,998)	(811,590)
Shares cancelled, shares	(1,936,812)	(5,252,026)
Total treasury shares at end of year	6,488,298	4,563,595	4,579,774
Total shares outstanding at end of year	87,098,120	90,959,635