Income Taxes (Schedule Of Components Of Provision For Income Taxes) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Currently payable:
Federal	$ 73,563,685	$ 83,010,387	$ 133,166,194
State	3,765,929	3,743,781	3,984,000
Foreign	1,468,018	1,776,837	2,440,000
Total	78,797,632	88,531,005	139,590,194
Deferred income tax (benefit) expense:
Primarily federal	(3,066,237)	(4,367,155)	(14,585,412)
Provision for income taxes	$ 75,731,395	$ 84,163,850	$ 125,004,782