Income Taxes (Schedule Of Components Of Provision For Income Taxes) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Currently payable:
Federal	$ 67,606,617	$ 73,563,685	$ 83,010,387
State	10,180,218	3,765,929	3,743,781
Foreign	1,882,195	1,468,018	1,776,837
Total	79,669,030	78,797,632	88,531,005
Deferred income tax benefit:
Primarily federal	(15,419,722)	(3,066,237)	(4,367,155)
Provision for income taxes	$ 64,249,308	$ 75,731,395	$ 84,163,850