Income Taxes (Schedule Of Components Of Provision For Income Taxes) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Currently payable:
Federal	$ 129,379,597	$ 108,689,911	$ 95,285,094
State	2,908,000	2,236,000	3,259,000
Foreign	276,000	978,000	1,353,000
Total	132,563,597	111,903,911	99,897,094
Net deferred:
Primarily federal	12,558,000	14,818,000	5,237,000
Provision for income taxes	$ 145,121,597	$ 126,721,911	$ 105,134,094