Income Taxes (Schedule Of Effective Income Tax Rate Reconciliation) (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
Statutory federal tax rate	21.00%	21.00%	21.00%
State and local income taxes, net of federal benefit	4.30%	4.50%	3.10%
Deemed repatriation of foreign earnings			(1.00%)
Effect of tax rate changes			(5.10%)
Meals and entertainment	0.50%	1.40%	1.40%
Other, net	0.80%	0.60%	0.40%
Effective tax rate	26.60%	27.50%	19.80%