Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($)	Common Stock [Member]	Paid-in Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income [Member]	Total
Balance at Dec. 31, 2017	$ 1,600	$ 14,780,100	$ 35,621,800	$ (3,036,800)	$ 0	$ 47,366,700
Balance (in shares) at Dec. 31, 2017	1,416,699
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	$ 0	0	317,300	0	0	317,300
Accumulated other comprehensive income						0
Balance at Mar. 31, 2018	$ 1,600	14,780,100	35,939,100	(3,036,800)	0	47,684,000
Balance (in shares) at Mar. 31, 2018	1,416,699
Balance at Dec. 31, 2018	$ 1,800	16,782,800	27,540,600	(3,037,300)	0	$ 41,287,900
Balance (in shares) at Dec. 31, 2018	1,545,884					1,545,884
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	$ 0	0	(1,308,200)	0	0	$ (1,308,200)
Accumulated other comprehensive income	0	0	0	0	(427,800)	(427,800)
Balance at Mar. 31, 2019	$ 1,800	$ 16,782,800	$ 26,232,400	$ (3,037,300)	$ (427,800)	$ 39,551,900
Balance (in shares) at Mar. 31, 2019	1,545,884					1,545,884