Consolidated Statements of Stockholders' Equity - USD ($)		Common Stock [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total		Cumulative Effect, Period of Adoption, Adjustment [Member] Retained Earnings [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member] Accumulated Other Comprehensive Income (Loss) [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member]
Balance at Dec. 31, 2017	[1]	$ 24,768	$ 3,939,589	$ (7,384,517)	$ 60,078,013	$ (762,313)	$ 55,895,540
Balance (in shares) at Dec. 31, 2017	[1]	9,270,862
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense		$ 0	28,969	0	0	0	28,969
Issuance of restricted stock		$ 40	(40)	0	0	0	0
Issuance of restricted stock (in shares)		16,648
Purchase of treasury stock		$ 0	0	$ (540,940)	0	0	(540,940)
Purchase of treasury stock (in shares)				(72,400)
Net income (loss)		0	0	$ 0	1,516,656	0	1,516,656
Foreign currency translation adjustments, net of tax		0	0	0	0	(58,992)	(58,992)
Balance at Mar. 31, 2018	[1]	$ 24,808	3,968,518	(7,925,457)	61,594,669	(821,305)	56,841,233
Balance (in shares) at Mar. 31, 2018	[1]	9,215,110
Balance at Dec. 31, 2017	[1]	$ 24,768	3,939,589	(7,384,517)	60,078,013	(762,313)	55,895,540
Balance (in shares) at Dec. 31, 2017	[1]	9,270,862
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	[1]						2,674,399
Foreign currency translation adjustments, net of tax	[1]						(343,766)
Balance at Jun. 30, 2018	[1]	$ 24,808	3,992,237	(8,379,703)	62,752,412	(1,106,079)	57,283,675
Balance (in shares) at Jun. 30, 2018	[1]	9,154,215
Balance at Mar. 31, 2018	[1]	$ 24,808	3,968,518	(7,925,457)	61,594,669	(821,305)	56,841,233
Balance (in shares) at Mar. 31, 2018	[1]	9,215,110
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense		$ 0	23,719	0	0	0	23,719
Purchase of treasury stock		0	0	$ (454,246)	0	0	(454,246)
Purchase of treasury stock (in shares)				(60,895)
Net income (loss)		0	0	$ 0	1,157,743	0	1,157,743	[1]
Foreign currency translation adjustments, net of tax		0	0	0	0	(284,774)	(284,774)	[1]
Balance at Jun. 30, 2018	[1]	$ 24,808	3,992,237	(8,379,703)	62,752,412	(1,106,079)	57,283,675
Balance (in shares) at Jun. 30, 2018	[1]	9,154,215
Balance at Dec. 31, 2018	[1]	$ 24,848	4,267,138	(9,037,783)	64,476,378	(1,444,185)	$ 58,286,396
Balance (Accounting Standards Update 2016-02 [Member]) at Dec. 31, 2018									$ (361,816)	$ 0	$ (361,816)
Balance (in shares) at Dec. 31, 2018	[1]						9,060,561
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense		0	185,825	0	0	0	$ 185,825
Issuance of restricted stock		$ 3	(3)	0	0	0	0
Issuance of restricted stock (in shares)		1,408
Purchase of treasury stock		$ 0	0	$ (714,617)	0	0	(714,617)
Purchase of treasury stock (in shares)				(127,945)
Net income (loss)		0	0	$ 0	1,519,811	0	1,519,811
Foreign currency translation adjustments, net of tax		0	0	0	0	314,493	314,493
Balance at Mar. 31, 2019	[1]	24,851	4,452,960	(9,752,400)	65,634,373	(1,129,692)	$ 59,230,092
Balance (in shares) at Mar. 31, 2019	[1]						8,934,024
Balance at Dec. 31, 2018	[1]	24,848	4,267,138	(9,037,783)	64,476,378	(1,444,185)	$ 58,286,396
Balance (Accounting Standards Update 2016-02 [Member]) at Dec. 31, 2018									$ (361,816)	$ 0	$ (361,816)
Balance (in shares) at Dec. 31, 2018	[1]						9,060,561
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)							$ 644,144
Foreign currency translation adjustments, net of tax							401,826
Balance at Jun. 30, 2019		24,851	4,644,896	(9,761,890)	64,758,706	(1,042,359)	$ 58,624,204
Balance (in shares) at Jun. 30, 2019							8,932,224
Balance at Mar. 31, 2019	[1]	24,851	4,452,960	(9,752,400)	65,634,373	(1,129,692)	$ 59,230,092
Balance (in shares) at Mar. 31, 2019	[1]						8,934,024
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense		0	191,936	0	0	0	$ 191,936
Purchase of treasury stock		0	0	$ (9,490)	0	0	(9,490)
Purchase of treasury stock (in shares)				(1,800)
Net income (loss)		0	0	$ 0	(875,667)	0	(875,667)	[2]
Foreign currency translation adjustments, net of tax		0	0	0	0	87,333	87,333
Balance at Jun. 30, 2019		$ 24,851	$ 4,644,896	$ (9,761,890)	$ 64,758,706	$ (1,042,359)	$ 58,624,204
Balance (in shares) at Jun. 30, 2019							8,932,224

[1] As described in Note 2 to these Consolidated Financial Statements, we have restated the Consolidated Financial Statements.

[2] For the three months ended June 30, 2019, there were 2,290 shares excluded from the diluted EPS calculation because the impact of their assumed vesting would be anti-dilutive due to a net loss in those periods.