Shareholders' Equity (Schedule Of Changes In Each Class Of Shares) (Details) - shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Beginning balance, Common Stock	1,012,261,159	1,012,261,159	1,012,261,159
Ending balance, Common Stock	1,012,261,159	1,012,261,159	1,012,261,159
Treasury Stock, Number of Shares and Restriction Disclosures [Abstract]
Beginning balance, Treasury Stock	395,109,568	345,637,354	305,533,606
Stock Issued During Period, Shares, Treasury Stock Reissued	20,746,426	6,376,868	7,288,113
Acquired, Treasury Stock	46,859,184	55,849,082	47,391,861
Ending balance, Treasury Stock	421,222,326	395,109,568	345,637,354