Statements of Stockholders' Equity - USD ($)	Class A Common Stock	Class C Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Retained Earnings	Treasury Stock	Total
Balance at Dec. 31, 2014	$ 24,918,480	$ 2,788,138	$ 25,931,119	$ 1,438,566	$ 44,101,252	$ (2,086,454)	$ 97,091,101
Net earnings					10,605,767		10,605,767
Other comprehensive income				413,315			413,315
Grant of stock options			299,986				299,986
Exercise of stock options	41,862	228,046	(1,208)			(244,009)	24,691
Sale of treasury stock			489,746			380,956	870,702
Stock Dividends	480	2	728		(1,210)
Conversion Class C to Class A	1,256	(1,256)
Balance at Sep. 30, 2015	24,962,078	3,014,930	26,720,371	1,851,881	54,705,809	(1,949,507)	109,305,562
Balance at Dec. 31, 2015	26,218,200	3,419,280	30,232,582	1,533,828	52,021,764	(2,179,429)	111,246,225
Net earnings					12,442,516		12,442,516
Other comprehensive income				491,220			491,220
Grant of stock options			253,427				253,427
Exercise of stock options	64,834		12,374				77,208
Sale of treasury stock			440,420			634,268	1,074,688
Stock Dividends	274	12,768	30,779		(43,821)
Conversion Class C to Class A	17,016	(17,016)
Balance at Sep. 30, 2016	$ 26,300,324	$ 3,415,032	$ 30,969,582	$ 2,025,048	$ 64,420,459	$ (1,545,161)	$ 125,585,284