Shareholders' Equity (Schedule Of Changes In Each Class Of Shares) (Details) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
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	449,352,405	444,619,970	421,222,326
Stock Issued During Period, Shares, Treasury Stock Reissued	19,986,868	2,797,002	3,409,330
Acquired, Treasury Stock	575,484	7,529,437	26,806,974
Ending balance, Treasury Stock	429,941,021	449,352,405	444,619,970