Income Taxes (Schedule Of Components Of Provision For Income Taxes) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Tax Disclosure [Abstract]
Currently payable, Federal	$ 76,507,760	$ 63,307,583	$ 54,032,045
Currently payable, State	2,450,000	1,663,000	789,000
Currently payable, Foreign	1,238,000	850,000	494,000
Currently payable, Total	80,195,760	65,820,583	55,315,045
Net deferred, Primarily federal	843,000	13,943,000	10,391,000
Provision for income taxes	$ 81,038,760	$ 79,763,583	$ 65,706,045