CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Unaudited) - USD ($)	Total	Common Stock	Additional Paid-In Capital	Accumulated other comprehensive loss	Retained Earnings (Accumulated Deficit)
Balance, shares at Dec. 31, 2019		8,386,145
Balance, amount at Dec. 31, 2019	$ 24,939,418	$ 83,861	$ 95,279,114	$ (242,594)	$ (70,180,963)
Common stock repurchased, shares		(2,416)
Common stock repurchased, amount	(10,113)	$ (24)	(10,089)	0	0
Stock compensation expense - restricted	254,499	0	254,499	0	0
Stock compensation expense non-qualified stock options	26,942	0	26,942	0	0
Foreign currency translation (loss)	(37,330)	0	0	(37,330)	0
Net income	483,888	$ 0	0		483,888
Balance, shares at Mar. 31, 2020		8,383,729
Balance, amount at Mar. 31, 2020	25,657,304	$ 83,837	95,550,466	(279,924)	(69,697,075)
Balance, shares at Dec. 31, 2019		8,386,145
Balance, amount at Dec. 31, 2019	24,939,418	$ 83,861	95,279,114	(242,594)	(70,180,963)
Foreign currency translation (loss)	55,159
Net income	2,039,478
Balance, shares at Sep. 30, 2020		8,458,734
Balance, amount at Sep. 30, 2020	40,551,723	$ 84,587	95,919,199	(187,435)	(68,141,485)
Balance, shares at Mar. 31, 2020		8,383,729
Balance, amount at Mar. 31, 2020	25,657,304	$ 83,837	95,550,466	(279,924)	(69,697,075)
Stock compensation expense - restricted	182,928	0	182,928	0	0
Stock compensation expense non-qualified stock options	26,499	0	26,499	0	0
Net income	488,627	$ 0	0	0	488,627
Issuance of common stock restricted, shares		58,123
Issuance of common stock restricted, amount	0	$ 581	(581)	0	0
Foreign currency translation gain	27,599	$ 0	0	27,599	0
Balance, shares at Jun. 30, 2020		8,441,852
Balance, amount at Jun. 30, 2020	26,382,957	$ 84,418	95,759,312	(252,325)	(69,208,448)
Stock compensation expense - restricted	133,266	0	133,266	0	0
Stock compensation expense non-qualified stock options	26,790	0	26,790	0	0
Foreign currency translation (loss)	64,890	0	0	64,890	0
Net income	1,066,963	$ 0	0	0	1,066,963
Issuance of common stock options exercises, shares		16,882
Issuance of common stock options exercises, amount	0	$ 169	(169)	0	0
Balance, shares at Sep. 30, 2020		8,458,734
Balance, amount at Sep. 30, 2020	40,551,723	$ 84,587	95,919,199	(187,435)	(68,141,485)
Balance, shares at Dec. 31, 2020		8,876,515
Balance, amount at Dec. 31, 2020	40,551,723	$ 8,876	100,504,741	(104,615)	(59,857,279)
Stock compensation expense - restricted	157,107	0	157,107	0	0
Stock compensation expense non-qualified stock options	25,735	0	25,735	0	0
Foreign currency translation (loss)	(54,949)	0	0	(54,949)	54,949
Net income	585,424	$ 0			585,424
Issuance of common stock restricted, shares		91,650
Issuance of common stock restricted, amount	(140,894)	$ 92	(140,986)	0	0
Issuance of common stock options exercises, shares		2,500
Issuance of common stock options exercises, amount	$ 10,250	$ 2	$ 10,248	0	0
Issuance of common stock through at-the-market offering program, net of issuance costs of $45,392, shares	1,088,398	100,687	1,088,297
Issuance of common stock through at-the-market offering program, net of issuance costs of $45,392, amount bb		$ 101
Balance, shares at Mar. 31, 2021		9,071,352
Balance, amount at Mar. 31, 2021	$ 42,222,794	$ 9,071	$ 101,645,142	(159,564)	(59,271,855)
Balance, shares at Dec. 31, 2020		8,876,515
Balance, amount at Dec. 31, 2020	40,551,723	$ 8,876	100,504,741	(104,615)	(59,857,279)
Foreign currency translation (loss)	(85,295)
Net income	$ 915,577
Issuance of common stock restricted, shares	12,526
Balance, shares at Sep. 30, 2021		9,138,146
Balance, amount at Sep. 30, 2021	$ 43,153,590	$ 9,138	102,276,064	(189,910)	(58,941,702)
Balance, shares at Mar. 31, 2021		9,071,352
Balance, amount at Mar. 31, 2021	42,222,794	$ 9,071	101,645,142	(159,564)	(59,271,855)
Stock compensation expense - restricted	214,852	0	214,852	0	0
Stock compensation expense non-qualified stock options	28,969	0	28,969	0	0
Foreign currency translation (loss)	19,633	0	0	19,633	0
Net income	(204,731)	$ 0	0	0	(204,731)
Issuance of common stock restricted, shares		28,208
Issuance of common stock restricted, amount	0	$ 29	(29)	0	0
Offering costs for the issuance of common stock At-the-market offering	(17,324)	$ 0	(17,324)	0	0
Balance, shares at Jun. 30, 2021		9,099,560
Balance, amount at Jun. 30, 2021	42,264,193	$ 9,100	101,871,610	(139,931)	(59,476,586)
Stock compensation expense - restricted	210,602		210,602
Stock compensation expense non-qualified stock options	24,867		24,867
Foreign currency translation (loss)	(49,979)			(49,979)
Net income	534,884	$ 0	0	0	534,884
Issuance of common stock options exercises, shares		38,586
Issuance of common stock options exercises, amount	169,023	$ 38	168,985
Balance, shares at Sep. 30, 2021		9,138,146
Balance, amount at Sep. 30, 2021	$ 43,153,590	$ 9,138	$ 102,276,064	$ (189,910)	$ (58,941,702)